Grammar Rule in 30 Seconds
Use 'than' for comparisons and 'then' for time or sequences.
- Use 'than' when comparing two things: 'A is better than B'.
- Use 'then' when talking about time: 'We ate, then we left'.
- Use 'then' for 'if/then' logic: 'If it rains, then stay inside'.
Overview
than と then です。中級レベル（B1）に到達した学習者であっても、急いでメールを書いている時や、英会話の最中にこれらを混同してしまうことは珍しくありません。しかし、この2つの単語は文法的な役割が根本から異なります。この違いを明確に理解し、正しく使い分けられるようになることは、あなたの英語の精度を一段階引き上げ、より自然でプロフェッショナルな表現を可能にするための重要なステップです。a と e）であること。そしてもう1つは、日常会話の速いスピードの中では、どちらも「弱形」として発音され、日本語の「ザン」や「ゼン」の中間のような、非常に曖昧な音（シュワ音 /ðən/）として聞こえるためです。ネイティブスピーカーでさえ、書き言葉でこれらを間違えることがあるほどです。than は「比較」の基準を示す言葉（〜よりも）、then は「時間」や「論理」の進展を示す言葉（その時、それから、それなら）です。このガイドでは、それぞれの役割を深く掘り下げ、日本人が陥りやすい罠を回避するためのポイントを詳しく解説していきます。than の主な役割は、2つのものを「比べる」ことです。日本語の助詞「〜よりも」に相当します。何かの性質や量、あるいは好みについて、AとBを対照させる際の「架け橋」となるのが than です。- 比較級とのセット:
taller（より高い）、more expensive（より高価な）といった比較級の形容詞や副詞の後に続きます。 - 不平等の提示: 2つの要素が「同じではない」ことを示し、どちらか一方が勝っている、あるいは劣っていることを表します。
then の役割は「時」の流れや「論理」のステップを示すことです。日本語では、文脈に応じて「その時」「それから」「それなら」と訳し分けられます。- 時間の流れ（Sequence）: 「まずAをして、次にBをする」という手順を説明する際に使います。
- 特定の時点（Point in time）: 過去や未来の「その瞬間」を指します。
- 論理的な帰結（Consequence）: 「もし〜なら、その時は（＝それなら）〜だ」という条件文の結果を導きます。
than | then |more, -er (比較級), rather | first, if, back, since |than は「横の並び（比較）」、then は「縦の流れ（時間・論理）」を司っていると考えると、イメージが湧きやすいはずです。- 1[比較級] +
than+ [比較対象]
My smartphone is newer than yours.
She speaks English more fluently than I do.
- 1[数量の比較] +
than
I have more than three pens.
It took less than an hour.
- 1Rather / Sooner +
than（好みや選択）
I would rather stay home than go out in the rain.
- 1[出来事A],
then[出来事B]（順序）
First, we had a meeting, then we went to lunch.
- 1If [条件],
then[結果]（論理）
If you are busy now, then I will call you later.
- 1[特定の時] +
then（時点）
I was living in Osaka back then.
Wait until Friday; I'll have more information then.
than を使うべきシチュエーション- ビジネスでの比較: 売上、コスト、効率などを前年や競合と比較する場合。
The production cost is higher than we expected.（製造コストが予想よりも高いです。）- 個人的な好みや選択: AよりBの方が好き、あるいはAするくらいならBしたいと言う場合。
I prefer tea rather than coffee.（コーヒーよりも紅茶を好みます。）- 「〜以外」と言うとき:
other thanというフレーズで使います。 I have no plans other than studying.（勉強すること以外に予定はありません。）
then を使うべきシチュエーション- 道案内や手順の説明: 「角を曲がって、それから直進してください」という場合。
Turn left at the convenience store, then walk for five minutes.（コンビニを左に曲がって、それから5分歩いてください。）- 過去の思い出話: 「あの頃は良かった」と振り返る場合。
Everything was cheaper back then.（当時はすべてがもっと安かった。）- 相手の話に対する反応: 「それなら、こうしましょう」と提案する場合。
A:（A「財布を忘れた」B「それなら、お金を貸してあげるよ」）I forgot my wallet.
B: "Then, I'll lend you some money."
then を使ってしまう- ❌ Mistake:
Tokyo is bigger then Osaka. - ⭕️ Correct:
Tokyo is bigger than Osaka. - 解説: 日本語では「東京は大阪より大きい」と言いますが、この「より」を英語にする際、音の響きが似ている
thenをつい選んでしまうミスです。特にタイピング時に起こりやすいですが、比較級（-er）を見たら、磁石のようにthanが引き寄せられると覚えておきましょう。
than を使ってしまう- ❌ Mistake:
If it rains, than the event will be canceled. - ⭕️ Correct:
If it rains, then the event will be canceled. - 解説: これは
thanとthenの綴りの混同から来ます。日本語の「もし〜なら、その時は」という時間のニュアンスが含まれる論理展開には、必ずthenを使います。thanには「もし〜なら」という文脈を支える力はありません。
- 解説: 冒頭でも触れた通り、ネイティブの日常会話では
thanもthenも非常に弱く発音されます。日本人は「ア」と「エ」をはっきり区別しようとしますが、英語ではどちらも「（口をあまり開けない）ン」に近い音になることがあります。そのため、耳から入った情報を文字にする際に間違えやすくなります。文法的な役割（比較か時間か）で判断する習慣をつけましょう。
than や then と似たような役割を持つ他の表現と比較してみましょう。これにより、使い分けの境界線がよりはっきりします。than vs. from (Different の後)different（異なる）という言葉の後、アメリカ英語では than が使われることもありますが、標準的には from が好まれます。different from | 最も一般的で標準的 | This plan is different from the original. |different than | 主にアメリカの口語 | This plan is different than I thought. |then vs. after / afterwardsthen | 文をつなぐ副詞。単独で「それから」 | I ate, then I slept. |after | 前置詞として後ろに名詞が必要 | After dinner, I slept. |afterwards | 文末や文頭で「その後で」と添える | I ate dinner. Afterwards, I slept. |No sooner ... than という表現を見かけましたが、これは then ではないのですか？then を使いたくなりますが、正解は than です。これは sooner という比較級が使われているため、文法的な呼応として than が選ばれています。古風で硬い表現ですが、TOEICやビジネス文書で見かけることがあります。No sooner had I arrived at the station than the train left.（駅に着くやいなや、電車が出てしまった。）then を使います。 See you then! というフレーズは、決まり文句として非常によく使われます。ここで See you than! と書いてしまうと、ネイティブには「〜よりもあなたに会う」という未完成で意味不明な文に見えてしまいますので注意しましょう。more than と over は同じですか？More than 100 people と Over 100 people はどちらも「100人より多い（101人以上）」を指します。ただし、more than の方がより一般的で、どんな文脈でも使いやすい表現です。than と then の違いをマスターするコツは、頭の中に「天秤（比較の than）」と「時計（時間の then）」のアイコンを思い浮かべることです。文を書くときに一瞬立ち止まって、「今、自分は何かを比べているかな？（天秤）」それとも「時間の流れや結果を話しているかな？（時計）」と自問自答してみてください。この小さな習慣が、あなたの英語をより正確で、信頼されるものに変えていくはずです。頑張りましょう！Comparison vs. Sequence
| Function | Word | Typical Preceding Word | Example |
|---|---|---|---|
|
Comparison
|
than
|
Comparative (Better/More)
|
Faster than a car
|
|
Time Sequence
|
then
|
First action
|
I ate, then I slept
|
|
Logical Result
|
then
|
If-clause
|
If you win, then you get a prize
|
|
Past Time
|
then
|
Preposition (Since/Back)
|
Back then, we were kids
|
Meanings
The distinction between 'than' (a conjunction used for comparisons) and 'then' (an adverb used to indicate time or consequence).
Comparison (Than)
Used to introduce the second element in a comparison.
“She is taller than her brother.”
“I have more than five dollars.”
Time Sequence (Then)
Used to indicate what happens next in a series of events.
“We went to the park, then we had lunch.”
“Finish your work, then you can play.”
Logical Consequence (Then)
Used in conditional 'if... then' structures.
“If you are tired, then go to sleep.”
“If 2+2 is 4, then 4-2 is 2.”
Reference Table
| 単語 | 役割 | 例文 |
|---|---|---|
|
`than`
|
比較
|
This episode is better `than` the last one.
|
|
`then`
|
時間・順序
|
First we'll eat, `then` we'll watch the movie.
|
|
`than`
|
比較
|
She has more experience `than` the other candidates.
|
|
`then`
|
結果 (If... then...)
|
If it rains, `then` the picnic is cancelled.
|
|
`than`
|
ratherと一緒に（好み）
|
I'd rather have coffee `than` tea.
|
|
`then`
|
特定の時を指す
|
I wasn't ready `then`, but I am now.
|
フォーマル度スペクトル
I should prefer tea rather than coffee. (ordering drinks)
I like tea more than coffee. (ordering drinks)
Tea's better than coffee. (ordering drinks)
Tea over coffee any day. (ordering drinks)
Than vs. Then: 究極の対決
どっちを使うべき？
2つのものを比較していますか？
時間、順番、または「それなら」について話していますか？
Than と Then の世界観
THAN (比較)
- Taller than comparison
- More than comparison
- Rather than preference
THEN (時間・順序)
- First..., then... sequence
- Back then past time
- If..., then... consequence
役割分担：Than と Then
Than の仕事
- • 価格を比べる
- • 好みを伝える
- • 順位をつける
Then の仕事
- • 手順を説明する
- • 物語を話す
- • 結果を述べる
レベル別の例文
He is taller than me.
He is taller than me.
I like apples more than oranges.
I like apples more than oranges.
I wash my hands, then I eat.
I wash my hands, then I eat.
See you then!
See you then!
This book is better than the movie.
This book is better than the movie.
It costs more than ten dollars.
It costs more than ten dollars.
We went to Paris, then to Rome.
We went to Paris, then to Rome.
If you are ready, then let's go.
If you are ready, then let's go.
I would rather stay home than go out tonight.
I would rather stay home than go out tonight.
There were more people than we expected.
There were more people than we expected.
Check the oil, then start the engine.
Check the oil, then start the engine.
He was much younger then.
He was much younger then.
The solution was more complex than it first appeared.
The solution was more complex than it first appeared.
No sooner had I arrived than the phone rang.
No sooner had I arrived than the phone rang.
If the results are inconclusive, then we must repeat the test.
If the results are inconclusive, then we must repeat the test.
But then again, we could just wait.
But then again, we could just wait.
The policy did more harm than good in the long run.
The policy did more harm than good in the long run.
Other than a few scratches, the car was fine.
Other than a few scratches, the car was fine.
The then-president signed the decree in 1994.
The then-president signed the decree in 1994.
Well, what are you waiting for then?
Well, what are you waiting for then?
Rarely has a man been more misunderstood than he.
Rarely has a man been more misunderstood than he.
The implications are more far-reaching than one might suppose.
The implications are more far-reaching than one might suppose.
Since then, the landscape has changed irrevocably.
Since then, the landscape has changed irrevocably.
If such be the case, then we are truly lost.
If such be the case, then we are truly lost.
間違えやすい
Learners sometimes say 'different than' instead of 'different from'.
The phrase 'No sooner had I...' must be followed by 'than', but people often use 'when' or 'then'.
Both can show consequence, but 'so' is a conjunction and 'then' is an adverb.
よくある間違い
He is bigger then me.
He is bigger than me.
I eat than I sleep.
I eat then I sleep.
More then five.
More than five.
Better then ever.
Better than ever.
First I go, than you go.
First I go, then you go.
I'd rather walk then run.
I'd rather walk than run.
If you win, than I pay.
If you win, then I pay.
No other then him.
No other than him.
Since than, I am sad.
Since then, I am sad.
More then likely.
More than likely.
The then-than president.
The then-president.
文型パターン
I like ___ more than ___.
First, ___, and then ___.
It was more ___ than I thought.
If ___, then ___.
Real World Usage
This laptop is faster than the one I have.
Whisk the eggs, then add the flour.
I have more than five years of experience in this field.
See u then!
The train is cheaper than the bus, but then we have to walk.
If the temperature rises, then the ice melts.
AとEで覚える裏技
He is taller than me.
スペルチェックは頼れない
You must be smarter than the machine.
「時々」を意味するフレーズ
I visit my parents every now and then.
正確さはプロの証
The result was better than expected.
Smart Tips
Check if you can replace the word with 'compared to'. If you can, use 'than'.
The second part of the sentence will almost always use 'then' (or an implied 'then').
Use 'then' to move the reader to the next step.
It is almost always followed by 'than'.
発音
The Schwa Effect
In normal conversation, both 'than' and 'then' are unstressed and sound like /ðən/. You must rely on context to understand which is being used.
Stressed 'Then'
When 'then' is at the end of a sentence or used for emphasis, the 'E' sound is clear.
Stressed 'Than'
When 'than' is stressed (rarely), it has a clear 'A' sound like 'apple'.
Sequence Intonation
First this (rise), then that (fall).
Shows a list of actions.
暗記しよう
記憶術
ThAn is for compArison (both have 'A'). ThEn is for timE (both have 'E').
視覚的連想
Imagine a giant letter 'A' acting as a balance scale between two objects (Comparison). Imagine a letter 'E' as a set of stairs leading from one event to the next (Time).
Rhyme
When you compare, 'than' is there. When time is the key, use the one with an 'e'.
Story
I wanted more THAN a sandwich. I went to the kitchen, THEN I made a feast. I ate it all, and THEN I felt better THAN before.
Word Web
チャレンジ
Write three sentences about your morning routine using 'then', and three sentences comparing your hometown to your current city using 'than'.
文化メモ
Mixing these up in writing is often seen as a sign of poor education or 'internet speak'. It is a very common 'pet peeve' for teachers and employers.
The word 'then' is frequently added to the end of questions to add a friendly or inquisitive tone, often without a specific 'time' meaning.
In some dialects, 'than' and 'then' are pronounced identically, making the written distinction even harder for native speakers in these regions.
Both words derive from the same Old English word 'þanne' or 'þænne'.
会話のきっかけ
Would you rather live in a very cold place or a very hot place? Why?
Tell me about your perfect morning. What do you do first, and what then?
Is learning English harder than you expected?
If you could change one thing about your city, what would it be and what would happen then?
日記のテーマ
よくある間違い
Test Yourself
than が正解です。then が使われている文が正しいです。then ではなく than を使う必要があります。Score: /3
練習問題
8 exercisesShe is much better at math ___ I am.
We went to the cinema, and ___ we went for pizza.
Find and fix the mistake:
I would rather travel by train then fly.
I will finish my homework, ___ I will call you.
You should use 'than' after the word 'more'.
A: Is your new car faster? B: Yes, it's much faster ___ my old one.
Which word is used for time?
If you are tired...
Score: /8
Practice Bank
12 exercisesI would rather read a book ___ watch that TV show.
Finish your homework, and ___ you can play video games.
正しい文章を選んでください：
正しい文章を選んでください：
He has more followers on Instagram then his friend.
If you are tired, than you should rest.
英語に訳してください：『プランAはプランBより安全です。』
英語に訳してください：『夕食を終えなさい、それからデザートを食べてもいいよ。』
単語を並べ替えて文を作ってください：
単語を並べ替えて文を作ってください：
文のペアを完成させてください：
The instructions were more complicated ___ I expected.
Score: /12
よくある質問 (8)
While people will understand you, it is still considered a mistake. It is better to use `than` to build good habits.
In English, unstressed vowels often turn into a 'schwa' sound (/ə/). This makes `than` and `then` sound nearly identical in fast speech.
It is always `more than` when comparing quantities or qualities.
You use it to mean 'in that case' or 'at that time'. For example: 'I'll see you `then`!'
No, the correct phrase is always `rather than`.
This is an advanced use where `then` acts like an adjective meaning 'at that time'. It refers to someone who was president in the past.
Rarely. It usually only happens in poetic or very formal inversions, like 'Than him, no one was more brave.'
Remember: Th**a**n = Comp**a**rison. Th**e**n = Tim**e**.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
que / entonces
Spanish doesn't have two words that sound almost identical for these two functions.
que / alors
The temporal 'then' has multiple distinct translations in French depending on the type of sequence.
als / dann
The word 'dann' sounds like 'than' but means 'then'.
yori / sorekara
Japanese grammar doesn't use conjunctions in the same position as English.
min / thumma
Arabic uses a preposition for comparison where English uses a conjunction.
bǐ / ránhòu
Chinese comparison structure (A bǐ B adjective) is completely different from English.
Learning Path
Prerequisites
関連動画
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