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A2 noun #1,000 most common 14 min read

先月

sengetsu Top 1,000

At the A1 level, learners are introduced to the absolute basics of Japanese temporal vocabulary, and 先月 (sengetsu) is one of the very first time-related words they encounter. The primary goal at this stage is simple communication about past events. Learners are taught to associate 先月 strictly with the past tense of verbs, usually in the polite ~ました (~mashita) form. For example, they learn to construct basic sentences like '先月、日本に行きました' (I went to Japan last month) or '先月、すしを食べました' (I ate sushi last month). The cognitive load at this level is focused on memorizing the vocabulary word itself and remembering not to use the particle に (ni) after it, which is a common interference error from English. Teachers emphasize rote memorization of the time sequence: 先月 (last month), 今月 (this month), and 来月 (next month). Students are not expected to understand the nuances of formal vs. informal usage or complex noun modification. The focus is purely on functional, survival-level communication, allowing the learner to narrate simple autobiographical facts about their recent past. Pronunciation practice is also key, ensuring the student says 'sengetsu' and not 'sengatsu'.

As learners progress to the A2 level, their use of 先月 becomes more integrated into slightly more complex sentence structures. They begin to use it not just as an isolated time marker, but in conjunction with other grammatical concepts. A key development at this stage is using the possessive particle の (no) to modify nouns, allowing them to say things like '先月のテスト' (last month's test) or '先月の給料' (last month's salary). This expands their expressive capability significantly, allowing them to discuss the attributes of past events or objects. Furthermore, A2 learners start combining 先月 with particles like から (kara - from/since) and まで (made - until). They learn to form sentences such as '先月から日本語を勉強しています' (I have been studying Japanese since last month), which introduces the concept of continuous action bridging the past and present. The contrastive marker は (wa) is also introduced in this context, enabling learners to make comparisons: '先月は忙しかったですが、今月は暇です' (Last month was busy, but this month is free). At this level, the vocabulary is firmly solidified, and the focus shifts to syntactic flexibility and combining 先月 with a wider variety of verbs and adjectives.

At the B1 level, learners are expected to have complete mastery over the basic grammatical functions of 先月. The focus shifts towards using the word in more diverse and natural conversational contexts. Learners begin to encounter and produce 先月 in informal speech, dropping the polite ~ます (~masu) endings and using the plain past tense (~た / ~ta form), such as '先月、映画見たよ' (I saw a movie last month). They also start to navigate basic business or administrative contexts where 先月 is frequently used, such as discussing bills ('先月のガス代' - last month's gas bill) or schedules. At this stage, learners should be able to self-correct if they accidentally use the に particle. Furthermore, B1 learners are introduced to related vocabulary that adds precision to their speech, such as 先々月 (sensengetsu - the month before last). They also begin to understand the semantic boundary of 先月, realizing that it strictly refers to the previous calendar month and not a rolling 30-day period, which is crucial for avoiding misunderstandings in practical situations like making reservations or discussing deadlines.

By the B2 level, the use of 先月 is largely automatic. The learner's challenge is no longer grammatical accuracy, but rather stylistic appropriateness and register. B2 learners are exposed to more formal environments, such as Japanese business settings, where they must understand the nuances between 先月 and its more formal counterpart, 昨月 (sakagetsu). While they will still primarily use 先月 in spoken communication, they must be able to read and comprehend 昨月 in emails and official documents. They also learn to use 先月 in complex, multi-clause sentences, such as relative clauses: '先月買ったパソコンがもう壊れました' (The computer I bought last month has already broken). Additionally, B2 learners encounter statistical and comparative language, learning phrases like '先月比' (sengetsu-hi - compared to last month) or '先月と比べて' (sengetsu to kurabete - compared to last month). They are expected to discuss trends, changes, and reasons for those changes, using 先月 as a foundational temporal anchor for their arguments and explanations. The word becomes a tool for complex discourse rather than just simple narration.

At the C1 level, learners possess near-native fluency in their use of temporal vocabulary. They manipulate 先月 effortlessly within highly sophisticated grammatical structures and across all social registers. They understand the subtle pragmatic implications of using 先月 in various contexts. For instance, they know how to use it in highly polite, humble language (Keigo) when speaking to superiors or clients: '先月は誠にお世話になりました' (I am truly grateful for your patronage last month). C1 learners are also fully comfortable with the distinction between 先月 (relative to the present) and 前月 (zengetsu - the previous month in a sequence), using them accurately when discussing historical data, financial reports, or sequential narratives. They can read complex news articles, economic analyses, and literature where these terms are used with precise technical or narrative intent. At this level, the learner's vocabulary is expansive enough that they can choose the exact temporal word needed for the specific rhetorical effect they desire, seamlessly integrating 先月 into idiomatic expressions and advanced conversational strategies.

At the C2 level, the learner's understanding and usage of 先月 are indistinguishable from an educated native speaker. They not only use the word flawlessly in all conceivable contexts but also possess a deep metalinguistic awareness of its role in the language. They can easily explain the etymology of the kanji, the phonetic rules governing its pronunciation (why it is 'getsu' and not 'gatsu'), and the cultural nuances of timekeeping in Japan. C2 learners can navigate highly specialized domains—such as law, advanced academia, or executive-level corporate finance—where temporal precision is paramount. They effortlessly interpret and produce complex documents utilizing 昨月, 前月, and 先月 appropriately. Furthermore, they can play with the language, understanding puns, literary references, or rhetorical devices that might rely on temporal shifts. For a C2 learner, 先月 is not just a vocabulary item; it is a fully integrated conceptual tool that they use to structure complex thoughts, articulate nuanced arguments, and engage deeply with Japanese culture and society at the highest levels of discourse.

Practice it Examples Notes & Tips

先月 in 30 Seconds

Means 'last month'.
Pronounced 'sengetsu', not 'sengatsu'.
Do not use the particle に (ni).
Always pair with past tense verbs.

Understanding the Japanese word 先月 (sengetsu) requires a deep dive into how the Japanese language conceptualizes time, specifically relative time. The word is composed of two distinct kanji characters: 先 (sen), which carries the meaning of 'previous', 'ahead', 'future', or 'first', and 月 (getsu), which translates directly to 'month' or 'moon'. When combined, these two characters form a highly frequent and essential temporal noun that English speakers translate as 'last month'.

Sentence 先月、日本に行きました。

In the context of Japanese grammar, temporal nouns play a fascinating role. Unlike specific dates or days of the week, relative time words like 先月 typically do not take the time particle に (ni). This is a crucial distinction for learners who might instinctively try to mirror English prepositions like 'in' or 'on'.

Grammar Rule: Relative time words do not require the particle に to function as time markers in a sentence.

Instead, 先月 functions directly as an adverbial noun within the sentence structure. For instance, if you want to say 'I went to Tokyo last month', you would say '先月、東京に行きました' (Sengetsu, Tokyo ni ikimashita), entirely omitting any particle after 先月. The beauty of this word lies in its absolute universality across all levels of Japanese society. Whether you are a student discussing a recent school trip, a business professional analyzing the previous quarter's sales figures, or a casual speaker chatting with friends about a recent movie release, 先月 is the appropriate and natural choice. It bridges the gap between formal and informal registers seamlessly. In formal business settings, you might hear it paired with humble or respectful language, such as '先月は大変お世話になりました' (Sengetsu wa taihen osewa ni narimashita - Thank you very much for your support last month).

Sentence 先月のレポートを提出しました。

In a casual setting, a simple '先月さ、' (Sengetsu sa, - You know, last month...) sets the stage for a personal anecdote. Furthermore, understanding 先月 opens the door to a broader pattern of time-related vocabulary in Japanese. Once a learner grasps the function of 先 (sen) in 先月, they can easily extrapolate its meaning in other words like 先週 (senshuu - last week) or 先日 (senjitsu - the other day).

Vocabulary Building: The kanji 先 is a highly productive prefix for past time expressions.

This morphological consistency is one of the features that makes Japanese vocabulary acquisition highly logical once the foundational building blocks are understood. However, learners must also be cautious of the nuances. While 先月 means 'last month', it refers strictly to the calendar month immediately preceding the current one.

Sentence 彼は先月から忙しいです。

If it is currently October, 先月 refers exclusively to September. It does not mean 'in the past 30 days' from the current date. For that specific meaning, one would need to use different phrasing, such as '過去一ヶ月' (kako ikkagetsu). This distinction is vital for accurate communication, especially in legal, medical, or business contexts where precise timelines are non-negotiable. Additionally, the pronunciation of 先月 is 'sengetsu', not 'sengatsu'. While the kanji 月 can be read as 'gatsu' in the names of the months (e.g., 一月 - ichigatsu - January), in relative time expressions, it is almost always read as 'getsu'.

Pronunciation Note: Always read 月 as 'getsu' in relative time words like 先月, 今月, and 来月.

Memorizing this phonetic rule early on prevents common pronunciation errors that can immediately mark a speaker as a novice. The cultural weight of the passing of a month is also significant in Japan, a country historically attuned to the changing of seasons and lunar cycles. The end of a month often brings specific administrative and social rituals, making the transition from 'this month' (今月) to 'last month' (先月) a frequent topic of conversation.

Sentence 先月の家賃を払いました。

In summary, mastering 先月 is not merely about memorizing a translation; it is about internalizing a core aspect of Japanese temporal grammar, recognizing kanji patterns, and understanding the cultural and practical contexts in which time is discussed in everyday Japanese life.

Sentence 私たちは先月結婚しました。

By fully grasping this single word, learners build a robust foundation for expressing past events clearly and naturally.

Using 先月 (sengetsu) correctly in a Japanese sentence is a fundamental skill that significantly improves a learner's ability to narrate past events. The syntactic placement of 先月 is relatively flexible, but it most commonly appears at the beginning of a sentence or immediately before the subject or topic. This positioning helps establish the temporal context right away, which is a common feature of Japanese sentence structure.

Sentence 先月、新しい車を買いました。

When you say '先月、新しい車を買いました' (Sengetsu, atarashii kuruma o kaimashita - I bought a new car last month), the word 先月 immediately informs the listener that the action occurred in the recent past. One of the most critical grammatical rules to remember is that 先月 is a relative time noun.

Particle Usage: Do not use the particle に (ni) after 先月. It is grammatically incorrect to say 先月に.

In Japanese, absolute time expressions (like specific dates, e.g., 'on the 5th' - 五日に) require the particle に to indicate the specific point in time. However, relative time expressions (words that change depending on the current date, like today, tomorrow, last week, last month) do not take this particle. Adding に after 先月 is a classic mistake made by English speakers who are translating the preposition 'in' from the phrase 'in the last month'. Another common way to use 先月 is by modifying other nouns using the possessive particle の (no). For example, if you want to talk about 'last month's sales', you would say '先月の売上' (sengetsu no uriage).

Sentence 先月の会議は長かったです。

This structure is incredibly versatile and is used constantly in both daily life and business. You can talk about 'last month's magazine' (先月の雑誌), 'last month's schedule' (先月の予定), or 'last month's weather' (先月の天気).

Noun Modification: Use 先月 + の + Noun to describe something that belonged to or occurred during the previous month.

Furthermore, 先月 can be combined with particles that indicate a starting point or a limit. For instance, the particle から (kara) means 'from' or 'since'. Therefore, '先月から' (sengetsu kara) translates to 'since last month'.

Sentence 私は先月から日本語を勉強しています。

This is particularly useful when combined with the present continuous tense (te-iru form) to express an action that started in the past and is still ongoing: '先月から日本語を勉強しています' (Sengetsu kara nihongo o benkyou shite imasu - I have been studying Japanese since last month). Conversely, the particle まで (made) means 'until'. While less common with 先月 than から, you might hear phrases like '先月まで東京に住んでいました' (Sengetsu made Tokyo ni sunde imashita - I lived in Tokyo until last month). It is also important to note the interaction between 先月 and the topic marker は (wa). When you want to contrast last month with this month, you can attach は directly to 先月.

Sentence 先月は雨が多かったです。

For example, '先月は忙しかったですが、今月は暇です' (Sengetsu wa isogashikatta desu ga, kongetsu wa hima desu - Last month was busy, but this month I am free). In this case, は highlights 先月 as the topic of discussion and sets up a contrast.

Contrastive Marker: Adding は to 先月 emphasizes it and often implies a contrast with another time period, like 今月 (this month).

Finally, always ensure that the main verb of your sentence is conjugated in the past tense when 先月 is the primary time marker, unless you are using the 'since last month' (先月から) structure. Saying '先月行きます' (Sengetsu ikimasu - I will go last month) is a logical contradiction and a grammatical error.

Sentence 先月、友達に会いました。

By mastering these syntactic patterns—omitting に, using の for possession, combining with から/まで, utilizing the contrastive は, and ensuring correct verb tense—learners can deploy 先月 with native-like fluency and precision in any conversational or written context.

The word 先月 (sengetsu) is ubiquitous in Japanese society, permeating almost every facet of daily life, business, media, and casual conversation. Because tracking time is a universal human necessity, you will encounter this word in a vast array of contexts, making it one of the highest-frequency temporal nouns you can learn.

Sentence ニュースで先月の事件について聞きました。

One of the most common places you will hear 先月 is in the workplace. Japanese business culture places a heavy emphasis on reporting, reviewing, and comparing data over time. Consequently, meetings and reports are filled with references to the previous month's performance.

Business Context: In corporate environments, 先月 is constantly used to discuss sales, expenses, and performance metrics.

You will frequently hear phrases like '先月の売上目標' (sengetsu no uriage mokuhyou - last month's sales target) or '先月比' (sengetsu-hi - compared to last month). When a manager asks for an update, they might say, '先月のデータを見せてください' (Sengetsu no deeta o misete kudasai - Please show me last month's data). Beyond the office, 先月 is a staple of everyday administrative life. When dealing with bills, rent, or subscriptions, the billing cycle is usually monthly.

Sentence 先月の電気代が高かったです。

Therefore, conversations with landlords, utility companies, or even just family members managing the household budget will inevitably involve this word. You might complain, '先月の電気代がすごく高かった' (Sengetsu no denkidai ga sugoku takakatta - Last month's electricity bill was really high), or confirm a payment by saying, '先月分はもう払いました' (Sengetsu-bun wa mou haraimashita - I already paid for last month's portion).

Daily Administration: Use 先月分 (sengetsu-bun) to refer to 'last month's share' or 'last month's charge' when paying bills.

In the realm of news and media, journalists and anchors use 先月 to provide temporal context for recent events. Whether reporting on economic trends, weather anomalies, or political developments, the phrase '先月行われた調査によると' (Sengetsu okonawareta chousa ni yoru to - According to a survey conducted last month) is a standard journalistic formula.

Sentence 先月、新しい法律ができました。

This helps the audience anchor the news story in a specific, recent timeframe. In casual, interpersonal communication, 先月 is the bridge to sharing recent life updates. When catching up with a friend you haven't seen in a while, you might recount a recent trip: '先月、北海道に旅行に行ったんだ' (Sengetsu, Hokkaido ni ryokou ni itta n da - I went on a trip to Hokkaido last month). It is also used in schools and educational settings. Teachers might remind students of previous lessons: '先月勉強した文法を覚えていますか' (Sengetsu benkyou shita bunpou o oboete imasu ka - Do you remember the grammar we studied last month?).

Sentence 先月のテストは難しかったです。

Students might discuss their recent exams or school events using the same vocabulary.

Educational Context: Commonly used to reference past curriculum, tests, or school events.

Furthermore, in the age of social media, people frequently use 先月 in their posts and captions to reflect on recent memories, often accompanied by photos. A post might read, '先月のカフェ巡り' (Sengetsu no kafe meguri - Last month's cafe hopping).

Sentence 先月の写真を見せてください。

Because it is so deeply embedded in the language, mastering the pronunciation, grammatical rules, and appropriate contexts for 先月 is absolutely essential for anyone aiming to achieve fluency and sound natural in Japanese.

While 先月 (sengetsu) is a relatively straightforward vocabulary word, English-speaking learners frequently stumble over a few specific grammatical and phonetic hurdles when first incorporating it into their Japanese. The most pervasive and stubborn mistake is the incorrect application of the time particle に (ni).

Sentence ❌ 先月に行きました。 ⭕ 先月行きました。

Because English relies heavily on prepositions like 'in', 'on', and 'at' to denote time (e.g., 'in the last month', 'on Monday'), learners naturally seek a Japanese equivalent. They learn that に is the time particle, so they logically, but incorrectly, construct sentences like '先月に日本へ行きました' (Sengetsu ni Nihon e ikimashita).

The 'Ni' Particle Error: Never attach に to relative time words like 先月, 今月, 来月, 昨日, 今日, or 明日.

This sounds unnatural to a native speaker. The correct formulation simply drops the particle: '先月、日本へ行きました'. Understanding the difference between absolute time (which takes に, like 'January' - 一月に) and relative time (which does not, like 'last month' - 先月) is a major milestone in Japanese grammar acquisition. Another frequent error involves verb tense mismatch. Because 先月 explicitly refers to the past, the main verb of the sentence must reflect this temporal reality.

Sentence ❌ 先月、東京に行きます。 ⭕ 先月、東京に行きました。

Beginners sometimes focus so hard on remembering the vocabulary word that they forget to conjugate the verb, resulting in sentences like '先月、映画を見ます' (Sengetsu, eiga o mimasu - I will watch a movie last month). This is jarring and confusing. The verb must be in the past tense: '見ました' (mimashita).

Tense Agreement: Always ensure the verb ending matches the time frame indicated by 先月 (usually ~ました or ~た).

The only exception is when using the continuous state marker ~ている (te iru) combined with から (kara - since), as in '先月から住んでいます' (Sengetsu kara sunde imasu - I have been living here since last month). Phonetically, learners often misread the kanji.

Sentence ❌ せんがつ (sengatsu) ⭕ せんげつ (sengetsu)

The kanji 月 has two common on'yomi (Chinese readings): 'gatsu' and 'getsu'. Because learners memorize the months of the year early on (一月 - ichigatsu, 二月 - nigatsu), they often overgeneralize this reading and pronounce 先月 as 'sengatsu'. This is incorrect. In relative time expressions (先月, 今月, 来月) and duration expressions (一ヶ月 - ikkagetsu), the reading is always 'getsu'. Furthermore, there is a semantic confusion regarding the scope of the word. English speakers sometimes use 'last month' to mean 'the past 30 days'.

Sentence 先月はカレンダーの前の月を指します。

If today is October 15th, 'in the last month' might mean September 15th to October 15th. In Japanese, 先月 strictly refers to the calendar month of September. If you want to express 'the past 30 days', you must use a phrase like 'ここ一ヶ月' (koko ikkagetsu) or '過去一ヶ月' (kako ikkagetsu).

Semantic Scope: 先月 means the previous calendar month, not a rolling 30-day period.

Using 先月 to mean a rolling 30-day period can lead to misunderstandings, particularly in business or medical contexts where precise timeframes are critical.

Sentence 先月の終わりまでに終わらせました。

By consciously avoiding the に particle, ensuring tense agreement, mastering the 'getsu' reading, and understanding the strict calendar definition, learners can easily overcome these common pitfalls and use 先月 with confidence.

While 先月 (sengetsu) is the standard, everyday word for 'last month', the Japanese language offers a rich tapestry of temporal vocabulary that allows for precise expression depending on the context, formality, and exact timeframe being discussed. Understanding these alternatives and related terms is crucial for advancing beyond basic proficiency.

Sentence ビジネスでは昨月という言葉も使われます。

The most direct synonym for 先月 is 昨月 (sakagetsu). The kanji 昨 (saku) means 'previous' or 'yesterday' (as seen in 昨日 - kinou/sakujitsu). 昨月 means exactly the same thing as 先月—the previous calendar month. However, 昨月 is significantly more formal and is almost exclusively reserved for written business correspondence, official documents, or highly formal speeches.

Formal Alternative: 昨月 (sakagetsu) is the formal, written equivalent of 先月. Use it in professional emails and reports.

You would rarely, if ever, use 昨月 in a casual conversation with a friend; doing so would sound unnaturally stiff and overly polite. Another related term is 前月 (zengetsu). While it also translates to 'the previous month', its usage is slightly different. 前月 is frequently used in financial, statistical, or sequential contexts where you are comparing one month to the month immediately preceding it, regardless of whether that month is relative to the present day. For example, if you are analyzing data from 2020, and you are looking at May's data, '前月' would refer to April 2020.

Sentence 売上は前月より上がりました。

先月, on the other hand, always anchors to the speaker's current present. If you need to refer to the month before last month, the word is 先々月 (sensengetsu).

Going Further Back: 先々月 (sensengetsu) means 'the month before last'. The repetition symbol 々 duplicates the 先 kanji.

This follows a logical pattern in Japanese temporal nouns (e.g., 先々週 - sensenshuu - the week before last). It is a very common and useful word in everyday conversation. Conversely, if you want to talk about the future, the antonyms are equally systematic.

Sentence 先々月、新しいパソコンを買いました。

'Next month' is 来月 (raigetsu), using the kanji 来 (rai - to come). 'This month' is 今月 (kongetsu), using 今 (kon/ima - now). 'The month after next' is 再来月 (saraigetsu). When learners want to express 'in the past month' (meaning a rolling 30-day period rather than the calendar month), they should use 過去一ヶ月 (kako ikkagetsu) or ここ一ヶ月 (koko ikkagetsu).

Sentence 過去一ヶ月の間に、三回映画を見ました。

For example, 'ここ一ヶ月、ずっと雨が降っています' (Koko ikkagetsu, zutto ame ga futte imasu - It has been raining constantly for the past month).

Duration vs. Point in Time: Use 一ヶ月 (ikkagetsu) for duration (one month long) and 先月 (sengetsu) for a point in time (last month).

By distinguishing between 先月 (standard relative past), 昨月 (formal written past), 前月 (sequential previous), and 過去一ヶ月 (rolling duration), learners can articulate precise temporal concepts across any social or professional register in Japanese.

Sentence 来月はもっと頑張ります。

This nuanced understanding is a hallmark of advanced language acquisition.

How Formal Is It?

Formal

Neutral

Informal

Child friendly

Slang

Fun Fact

The kanji 先 (sen) can mean both 'past' (as in 先月 - last month) and 'future' (as in 先のこと - things in the future). This is because time is conceptualized as a line where what is 'ahead' of you on the path is the future, but what has 'gone ahead' of you in time is the past.

Pronunciation Guide

UK /seŋ.ɡe.tsɯ/

US /sɛŋ.ɡɛ.tsu/

In standard Tokyo pitch accent, 先月 has a 'heiban' (flat) pitch. It starts low on 'se', goes high on 'n', and stays high for 'ge' and 'tsu'.

Rhymes With

来月 (raigetsu) 今月 (kongetsu) 前月 (zengetsu) 昨月 (sakagetsu) 毎月 (maigetsu) 半月 (hangetsu) 満月 (mangetsu) 正月 (shougatsu - note the different reading, but similar ending sound)

Common Errors

Pronouncing it 'sengatsu'. Remember, relative time uses 'getsu'.
Pronouncing the 'tsu' as 'su'. It must have the 't' sound.
Putting English-style stress on the first syllable. Keep the pitch flat.
Rounding the final 'u' too much. Japanese 'u' is unrounded.
Separating the 'n' and 'g' too much. Let them blend slightly.

Difficulty Rating

Reading 2/5

The kanji are very basic (taught in 1st grade in Japan). The only difficulty is remembering the 'getsu' reading instead of 'gatsu'.

Writing 1/5

Both kanji have very few strokes and are foundational.

Speaking 2/5

Easy to pronounce, but learners must remember to drop the 'ni' particle.

Listening 1/5

Very distinct and easy to catch in conversation.

What to Learn Next

Prerequisites

月 (tsuki - month) 行く (iku - to go) 食べる (taberu - to eat) 昨日 (kinou - yesterday) 今日 (kyou - today)

Learn Next

今月 (kongetsu - this month) 来月 (raigetsu - next month) 先週 (senshuu - last week) 去年 (kyonen - last year) 先々月 (sensengetsu - month before last)

Advanced

昨月 (sakagetsu - last month formal) 前月 (zengetsu - previous month) 一ヶ月前 (ikkagetsumae - one month ago) 先月比 (sengetsuhi - month-over-month) 先月度 (sengetsudo - last month's period)

Grammar to Know

Relative Time Words (No Particle に)

先月、行きました。 (Not 先月に行きました)

Noun Modification with の

先月のテスト (Last month's test)

Past Tense Verbs (~ました / ~た)

先月、買いました。 (Bought last month)

Continuous Action with から ~ている

先月から住んでいます。 (Living here since last month)

Contrast with は

先月は暇でした。 (As for last month, I was free)

Examples by Level

先月、日本に行きました。

I went to Japan last month.

Uses basic past tense polite form (~ました).

先月は暑かったです。

Last month was hot.

Uses past tense for i-adjectives (~かったです).

先月、カメラを買いました。

I bought a camera last month.

Basic object marker (を) with past tense verb.

先月、友達に会いました。

I met a friend last month.

Uses particle に for the target of meeting.

先月はひまでした。

I was free last month.

Uses past tense for na-adjectives/nouns (~でした).

先月、本を読みました。

I read a book last month.

Basic past tense action.

先月、映画を見ました。

I watched a movie last month.

Basic past tense action.

先月、すしを食べました。

I ate sushi last month.

Basic past tense action.

先月のテストは難しかったです。

Last month's test was difficult.

Uses の to modify a noun (先月の + Noun).

先月から日本語を勉強しています。

I have been studying Japanese since last month.

Uses から with ~ています for continuous action.

先月は忙しかったですが、今月は暇です。

Last month was busy, but this month I am free.

Uses は for contrast between two time periods.

先月買ったくつが、もう古くなりました。

The shoes I bought last month have already gotten old.

Uses a relative clause (先月買った + Noun).

先月の給料で新しいカバンを買いました。

I bought a new bag with last month's salary.

Uses で to indicate the means/source.

先月まで東京に住んでいました。

I lived in Tokyo until last month.

Uses まで to indicate the end point of a state.

先月の会議で、新しいプロジェクトが決まりました。

A new project was decided at last month's meeting.

Uses で to indicate the location/context of an event.

先月の電気代はいくらでしたか。

How much was last month's electricity bill?

Asking a question about a past state/attribute.

先月、京都に行ったんだけど、すごく綺麗だったよ。

I went to Kyoto last month, and it was really beautiful.

Uses informal speech and explanatory ~んだけど.

先月の売上は、目標に届きませんでした。

Last month's sales did not reach the target.

Business vocabulary context.

先月貸した本、もう読んだ？

Have you read the book I lent you last month yet?

Informal relative clause modifying a noun.

先月は雨ばかり降っていて、どこにも行けなかった。

It did nothing but rain last month, so I couldn't go anywhere.

Uses ~ばかり (nothing but) and potential negative form.

先月分の家賃を振り込むのを忘れてしまいました。

I completely forgot to transfer last month's rent.

Uses ~分 (portion) and ~てしまう (regret/completion).

先月始めたアルバイトにも、だいぶ慣れてきました。

I've gotten quite used to the part-time job I started last month.

Uses ~てくる to show a change in state over time.

先月と比べて、今月は少し涼しいですね。

Compared to last month, it's a little cooler this month, isn't it?

Uses ~と比べて (compared to).

先月は残業が多かったので、今月は少し休みたいです。

I had a lot of overtime last month, so I want to rest a bit this month.

Uses ので for cause and effect.

先月比で売上が10パーセント増加した。

Sales increased by 10 percent compared to last month.

Uses the business suffix ~比 (ratio/comparison).

先月提出していただいた企画書ですが、いくつか修正をお願いします。

Regarding the proposal you submitted last month, I would like to request a few corrections.

Uses humble receiving form ~ていただく.

先月からの懸案事項について、本日の会議で結論を出したいと思います。

I would like to reach a conclusion in today's meeting regarding the pending issue from last month.

Formal vocabulary (懸案事項) and structure.

先月は体調を崩しがちだったので、今月は健康管理に気をつけます。

I tended to get sick last month, so I will be careful about my health management this month.

Uses ~がち (tendency) to describe a past state.

先月発売されたばかりのスマートフォンが、もう品切れになっているそうだ。

I hear that the smartphone that was just released last month is already out of stock.

Uses ~たばかり (just did) and hearsay ~そうだ.

先月お会いした際には、十分なご挨拶ができず申し訳ありませんでした。

I apologize that I was not able to greet you properly when we met last month.

Highly formal Keigo (お会いした際, 申し訳ありませんでした).

先月のデータをもとに、来期の戦略を立てる必要がある。

We need to formulate next term's strategy based on last month's data.

Uses ~をもとに (based on).

先月は予期せぬトラブルが相次ぎ、対応に追われました。

Unexpected troubles occurred one after another last month, and we were swamped dealing with them.

Advanced vocabulary (予期せぬ, 相次ぐ, 追われる).

先月の取締役会で承認された予算案に基づき、プロジェクトを推進していく所存です。

We intend to promote the project based on the budget proposal approved at last month's board of directors meeting.

Highly formal business/executive language (~所存です).

先月の統計データは、景気の緩やかな回復基調を裏付けるものとなった。

Last month's statistical data served to substantiate the gradual recovery trend of the economy.

Academic/journalistic register.

先月来の円安傾向が、輸出企業に追い風となっている。

The trend of the weak yen since last month is acting as a tailwind for export companies.

Uses ~来 (since) in a formal context.

先月お送りした書面と重複する部分もございますが、改めてご説明申し上げます。

Although there are parts that overlap with the document I sent last month, I will explain it to you once again.

Advanced Keigo and formal correspondence style.

先月の事件を契機として、セキュリティ体制の抜本的な見直しが図られた。

Taking last month's incident as an opportunity, a fundamental review of the security system was undertaken.

Uses ~を契機として (as an opportunity/trigger).

先月は公私ともに多忙を極め、心身ともに疲労困憊であった。

Last month, I was extremely busy both publicly and privately, and was exhausted both mentally and physically.

Literary/dramatic expression (多忙を極め, 疲労困憊).

先月の法改正に伴い、当社のコンプライアンス規定も改定を余儀なくされた。

In accordance with last month's legal revision, our company's compliance regulations were also forced to be revised.

Uses ~に伴い (along with) and ~を余儀なくされる (forced to).

先月の時点で既にその兆候は表れていたにもかかわらず、誰も気付かなかった。

Even though the signs had already appeared as of last month, no one noticed.

Uses ~時点で (at the time of) and ~にもかかわらず (despite).

先月の業績悪化は、単なる一過性の現象ではなく、構造的な問題に起因していると推察される。

It is inferred that last month's performance deterioration is not merely a transient phenomenon, but originates from structural problems.

Academic/analytical register with complex vocabulary.

先月来の議論の紛糾は、双方の前提条件に対する認識の齟齬から生じたものである。

The complication of the arguments since last month arose from a discrepancy in the perception of the preconditions on both sides.

Highly abstract and formal vocabulary (紛糾, 齟齬).

先月の手紙に綴られていた彼女の心情を察するに余りある。

It is more than I can bear to imagine her feelings that were spelled out in last month's letter.

Literary expression (~に余りある).

先月の株主総会における紛糾は、経営陣のガバナンス欠如を如実に物語っている。

The turmoil at last month's general shareholders' meeting vividly illustrates the management team's lack of governance.

Executive corporate vocabulary.

先月の判例変更は、今後の実務に甚大な影響を及ぼすことが必至である。

It is inevitable that last month's change in judicial precedent will exert a profound impact on future practice.

Legal terminology and formal predictive phrasing (~必至である).

先月のあの発言が、彼の政治生命を絶つ致命傷となったのは疑いようもない事実だ。

It is an indubitable fact that that remark last month became the fatal wound that ended his political life.

Dramatic journalistic/political commentary.

先月のシンポジウムで提示された仮説は、既存のパラダイムを根底から覆す可能性を秘めている。

The hypothesis presented at last month's symposium holds the potential to fundamentally overturn the existing paradigm.

Academic/scientific register.

先月の凶作が引き金となり、農村部ではかつてない規模の飢饉が懸念されている。

Triggered by last month's poor harvest, there are fears of a famine of unprecedented scale in the rural areas.

Historical/sociological narrative style.

Common Collocations

先月の売上

先月比

先月末

先月分

先月中

先月上旬

先月中旬

先月下旬

先月いっぱいで

先月以来

Common Phrases

先月はありがとうございました

先月のことですが

先月と同じ

先月からずっと

先月に引き続き

先月はどうでしたか

先月の今頃

先月の予定

先月の会議で

先月の支払い

Often Confused With

先月 vs 先週 (senshuu)

Means 'last week'. Both start with 先 (sen), so learners sometimes mix them up.

先月 vs 来月 (raigetsu)

Means 'next month'. Learners sometimes confuse the past and future terms.

先月 vs 一ヶ月前 (ikkagetsumae)

Means 'one month ago' (exactly 30 days ago), whereas 先月 means the calendar month.

Idioms & Expressions

"先月いっぱいで"

By the end of last month. Often used when quitting a job or ending a contract.

先月いっぱいで会社を退職しました。

Neutral

"先月をもちまして"

As of last month. A very formal way to announce the end of something.

先月をもちまして、本サービスは終了いたしました。

Formal

"先月からの持ち越し"

Carried over from last month. Used for tasks or budgets.

この仕事は先月からの持ち越しです。

Business

"先月分のツケ"

The tab/bill from last month. Often used in bars or casually for debts.

先月分のツケを払いに来たよ。

Informal

"先月の雪"

Something that is completely in the past and irrelevant now (rare/poetic).

それはもう先月の雪のような話だ。

Literary

"先月比マイナス"

A decrease compared to last month. A standard business phrase.

今月の売上は先月比マイナスです。

Business

"先月比プラス"

An increase compared to last month.

利益は先月比プラスに転じました。

Business

"先月の穴埋め"

Making up for last month's deficit or mistakes.

今月は先月の穴埋めをしなければならない。

Neutral

"先月の二の舞"

Repeating last month's mistake/failure.

先月の二の舞にならないように気をつけよう。

Neutral

"先月の成績を引っ張る"

To be dragged down by last month's (poor) results.

先月の成績を引っ張って、今月も調子が悪い。

Neutral

Easily Confused

先月 vs 昨月 (sakagetsu)

Means exactly the same thing as 先月.

昨月 is highly formal and mostly used in written business documents. 先月 is the standard word for spoken and general written Japanese.

昨月は大変お世話になりました。(Formal email)

先月 vs 前月 (zengetsu)

Also translates to 'previous month'.

前月 is used in sequences or comparisons (e.g., 'the month before that one'), not necessarily relative to today. 先月 is always relative to the current month.

5月の売上は、前月（4月）より高い。(Comparing May to April)

先月 vs 先々月 (sensengetsu)

Looks and sounds similar.

先々月 means 'the month before last'. It goes one month further back than 先月.

先々月に日本へ来ました。(Came two months ago)

先月 vs 過去一ヶ月 (kako ikkagetsu)

English speakers use 'last month' to mean 'the past 30 days'.

先月 is the calendar month (e.g., September). 過去一ヶ月 is the rolling 30-day period from today.

過去一ヶ月で3キロ痩せました。(Lost 3kg in the past 30 days)

先月 vs せんがつ (sengatsu)

A common mispronunciation.

This is not a word. The correct pronunciation is せんげつ (sengetsu). 'Gatsu' is only used for the names of the months (January, February, etc.).

❌ せんがつ ⭕ せんげつ

Sentence Patterns

先月、[Place] に行きました。

先月、東京に行きました。

先月、[Object] を [Verb past tense]。

先月、車を買いました。

先月の [Noun] は [Adjective past tense]。

先月のテストは難しかったです。

先月から [Verb te-iru form]。

先月から日本語を勉強しています。

先月は [Reason] ので、[Result]。

先月は忙しかったので、どこにも行けませんでした。

先月 [Verb plain past] [Noun] が [Verb]。

先月買ったパソコンが壊れました。

先月と比べて、[Noun] が [Verb/Adjective]。

先月と比べて、売上が上がりました。

先月の [Noun] に伴い、[Result]。

先月の法改正に伴い、ルールが変わりました。

Word Family

Nouns

Verbs

How to Use It

frequency

Extremely High. Top 1000 most common words in Japanese.

Common Mistakes

先月に日本へ行きました。 → 先月、日本へ行きました。
Do not use the particle に (ni) with relative time words like 先月. It is grammatically incorrect.
先月、東京に行きます。 → 先月、東京に行きました。
先月 refers to the past, so the verb must be conjugated in the past tense (~ました).
せんがつ (sengatsu) → せんげつ (sengetsu)
The reading for 月 in relative time words is 'getsu', not 'gatsu'. 'Gatsu' is only for calendar months (e.g., 一月).
過去一ヶ月に日本へ行きました。(When meaning 'last month') → 先月、日本へ行きました。
過去一ヶ月 means 'in the past 30 days'. If you mean the previous calendar month, you must use 先月.
先月テストは難しかったです。 → 先月のテストは難しかったです。
When a time noun modifies another noun, you must connect them with the possessive particle の (no).

Tips

Drop the 'Ni'

Never say 先月に. It is a classic beginner mistake. Always omit the time particle for relative time words.

Getsu, not Gatsu

Train yourself to associate relative time (last, this, next month) with the 'getsu' reading. Only calendar names use 'gatsu'.

The 'Sen' Family

Learn 先月 (last month), 先週 (last week), and 先日 (the other day) together. They all use the 先 (previous) kanji.

Calendar Month Only

Remember that 先月 means the block on the calendar before this one, not a rolling 30-day period.

Using 'No' for Possession

To talk about things from last month, use の. 先月のテスト (last month's test), 先月の給料 (last month's salary).

Since Last Month

Use 先月から + ~ています to express something you started last month and are still doing. (先月から勉強しています).

Formal Alternative

If you are writing a very formal business email, impress your boss by using 昨月 (sakagetsu) instead of 先月.

Going Further Back

Add one more 先 to make 先々月 (sensengetsu), which means the month before last.

Contrasting Months

Use the particle は to contrast: 先月は忙しかったですが、今月は暇です (Last month was busy, but this month is free).

Kanji Strokes

The kanji 先 has 6 strokes and 月 has 4. They are very basic and essential to memorize early on.

Memorize It

Mnemonic

SENd GETSU (gets you) back to LAST MONTH. Imagine you SENd a letter that GETS to its destination LAST MONTH via a time machine.

Visual Association

Picture a calendar. You are pointing your finger (先 - saki/point) at the moon (月 - getsu) drawn on the page for the PREVIOUS month.

Word Web

先 (Previous) -> 先週 (Last week), 先日 (The other day) 月 (Month) -> 来月 (Next month), 今月 (This month) Time -> 過去 (Past) Calendar -> カレンダー (Calendar)

Challenge

Look at your calendar right now. Say the name of the current month in English, then point to the previous month and say '先月' out loud. Then try to make a sentence about what you did in that month.

Word Origin

The word 先月 is a Sino-Japanese compound (kango). It combines the kanji 先, meaning 'ahead', 'previous', or 'future' (depending on context, here meaning 'previous in time'), and 月, meaning 'moon' or 'month'. This combination reflects the ancient Chinese method of tracking time using lunar cycles.

Original meaning: Originally, it literally meant 'the previous moon cycle'.

Sino-Japanese (Kango)

Cultural Context

No specific cultural sensitivities. It is a completely neutral and safe word to use in any context.

English speakers often say 'in the last month' to mean a 30-day period. In Japanese, 先月 strictly means the calendar month. Be careful not to translate the English idiom directly.

News broadcasts constantly use '先月' when reporting on recent economic data. Corporate earnings reports. Daily conversation about weather transitions.

Practice in Real Life

Real-World Contexts

Talking about recent trips or events.

先月、旅行に行きました
先月のイベント
先月はどうでしたか
先月は楽しかったです

Discussing bills and expenses.

先月の電気代
先月分の家賃
先月のカードの支払い
先月は使いすぎた

Business reporting.

先月の売上
先月比で増加
先月の会議の議事録
先月の目標

Talking about ongoing states.

先月から忙しい
先月から勉強している
先月から住んでいる
先月からずっと雨

Contrasting time periods.

先月は良かったが今月は悪い
先月と比べて
先月と同じ
先月とは違う

Conversation Starters

"先月はどこかに出かけましたか？ (Did you go anywhere last month?)"

"先月見た映画で、おすすめはありますか？ (Are there any movies you saw last month that you recommend?)"

"先月は忙しかったですか？ (Were you busy last month?)"

"先月の電気代、高かったですよね？ (Last month's electricity bill was high, wasn't it?)"

"先月から何か新しいことを始めましたか？ (Have you started anything new since last month?)"

Journal Prompts

先月の一番の思い出は何ですか？ (What is your best memory from last month?)

先月、新しく学んだことは何ですか？ (What is something new you learned last month?)

先月の目標は達成できましたか？ (Were you able to achieve last month's goals?)

先月と今月を比べて、何が変わりましたか？ (Comparing last month and this month, what has changed?)

先月のお金の使い方を振り返ってみましょう。 (Let's reflect on how you spent money last month.)

Frequently Asked Questions

10 questions

No. 先月 is a relative time word. In Japanese, you do not use に after relative time words like today, tomorrow, last week, or last month. Just say '先月、行きました' (Sengetsu, ikimashita).

The kanji 月 has two common readings: 'gatsu' and 'getsu'. 'Gatsu' is used for the names of the calendar months (e.g., 一月 - ichigatsu - January). 'Getsu' is used for relative time periods (先月, 今月, 来月) and durations (一ヶ月).

No. 先月 strictly refers to the previous calendar month. If today is October 15th, 先月 means September. If you want to say 'in the past 30 days', use 過去一ヶ月 (kako ikkagetsu).

They mean the same thing, but 昨月 (sakagetsu) is much more formal. You will see 昨月 in business emails and official documents, but you should use 先月 in normal conversation.

You use the possessive particle の (no). 'Last month's rent' is 先月の家賃 (sengetsu no yachin). If you want to say 'the portion for last month', you can say 先月分 (sengetsu-bun).

Generally, no. Because it refers to the past, the main verb should be in the past tense (~ました). The exception is when using から (since), as in '先月から住んでいます' (I have been living here since last month).

The opposite is 来月 (raigetsu), which means 'next month'. The current month is 今月 (kongetsu).

You say 先々月 (sensengetsu). The kanji 々 means to repeat the previous kanji, so it literally means 'previous previous month'.

Yes, 先月 is perfectly acceptable in business Japanese. However, in highly formal written documents, 昨月 (sakagetsu) is sometimes preferred.

It is written as せんげつ (sengetsu).