Grammar Rule in 30 Seconds
The Future Perfect describes an action that will be finished before a specific point in the future.
- Use 'will have' + the past participle (e.g., 'will have eaten').
- It always looks back from a future point to a completed action.
- Commonly used with 'by' or 'by the time' (e.g., 'by tomorrow').
Overview
Future Perfect（未来完了形）です。日本語には英語のような厳密な「時制（Tense）」の区別がなく、特に「未来のある時点ですでに何かが終わっている状態」を一つの動詞の形で表す習慣がないため、最初は少し戸惑うかもしれません。will have done をマスターすると、あなたの英語は一気に「正確」で「知的」なものに変わります。例えば、ビジネスでの締め切り、旅行の計画、あるいは日常の何気ない約束において、「いつまでに〜し終えている」という明確なタイムラインを提示できるようになるからです。単に will do（〜するつもりだ）と言うよりも、未来の特定の時点を見据えた「完了」を意識させることで、相手に安心感や信頼感を与えることができます。will（未来）と have + 過去分詞（完了）を組み合わせることで、一つの時制としてこれを厳密に区別します。Future Simple (will sleep) | 単なる未来の予定・動作 |Future Continuous (will be sleeping) | 未来の特定の瞬間に進行中の動作 |Future Perfect (will have slept) | 未来の特定の時点ですでに完了している状態 |I will have finished the work by Friday. という文章が成立します。has に変える必要もありません。これは、助動詞 will の後ろには必ず動詞の原形が来るという英語の鉄則があるためです。Subject + will + have + Past Participle (過去分詞)- 肯定文:
I will have finished the report by tomorrow.（明日までにはレポートを書き終えているでしょう。） - 否定文:
I will not (won't) have finished the report by tomorrow.（明日までにはレポートは終わっていないでしょう。） - 疑問文:
Will you have finished the report by tomorrow?（明日までにレポートを書き終えていますか？）
- 1主語が何であっても
will have:
He will have..., She will have..., They will have...。三人称単数の s を気にする必要がないため、現在完了形よりも形成自体は簡単です。- 1過去分詞 (Past Participle):
finished, worked）だけでなく、不規則動詞（gone, written, done, seen）もしっかりと覚えている必要があります。特に written や taken など、日常的に使う不規則動詞の過去分詞形を瞬時に出せるようにしておきましょう。- 1短縮形:
I'll have, You'll have, He'll have といった短縮形が頻繁に使われます。また、否定形の won't have も非常によく使われるため、耳に慣れておくことが大切です。by（〜までに）や by the time（〜する時までに）といった表現と一緒に使われることが非常に多いです。By the time the train arrives at Shinjuku, I will have finished reading this book.
The construction will have been completed by next March.
for を使って期間を表すこともあります。By next month, I will have lived in Tokyo for ten years.
If she visits Kyoto again, she will have been there five times.
When you get home, I will have cooked dinner.
He will have heard the news already.
by と until の混同（最大の間違い）by がよく使われますが、日本人はこれを until と間違えることが非常に多いです。- 間違い:
I will have finished it until 5 PM. - 正解:
I will have finished it by 5 PM. - 理由:
untilは「継続（ずっと〜し続ける）」を表し、byは「期限（その時までに完了する）」を表します。未来「完了」形は動作の終わりを指すため、継続を表すuntilとは相性が悪いのです。
will has と言ってしまう- 間違い:
He will has finished the task. - 正解:
He will have finished the task. - 理由: 助動詞
willの直後は必ず「原形」でなければなりません。hasは三人称単数現在形であり、原形はhaveです。これは中級者でもうっかりやってしまうミスです。
when や by the time）の中の時制ミス- 間違い:
By the time you will arrive, I will have finished. - 正解:
By the time you arrive, I will have finished. - 理由: 時や条件を表す副詞節（
when,if,by the timeなど）の中では、未来のことでも現在形を使うというルールがあります。メインの文章（主節）が未来完了形であっても、このルールは適用されます。
I will finish it tomorrow. | 明日それを終わらせるという「意志」や「予定」を単に述べている。 |I will be finishing it tomorrow. | 明日の特定の時間に、それを終わらせる作業を「している最中」であることを強調。 |I will have finished it by tomorrow. | 明日のある時点では、その作業は「すでに完了している」という結果に焦点を当てている。 |I will prepare the materials.(資料を準備します。＝ 単なる宣言)I will be preparing the materials at 3 PM.(3時には資料を準備している最中です。＝ 進行状況)I will have prepared the materials by the time the meeting starts.(会議が始まるまでには、資料の準備は終わっています。＝ 完了の保証)
Future Perfect です。いつまでに何が終わっているかを明確に伝えることができるからです。I'll be done by 5.（5時までには終わるよ）のように、be done を使って代用されることもありますが、will have finished を使うとより正確でプロフェッショナルな響きになります。will have done と will have been doing（未来完了進行形）はどう使い分けますか？will have done は「完了した結果」に注目します。一方、will have been doing は「その時までずっと続けている」という「動作の継続」そのものに注目します。例えば、「来月で10年働いていることになる」という場合、どちらも使えますが、進行形を使うと「ずっと頑張って働き続けてきた」というニュアンスが強まります。should は使えますか？It should have been finished by now.（今頃はもう終わっているはずだ）のように使います。ただし、will have done の方が should よりも確信度が高く、「間違いなく終わっている」という強い予測や意志を表現できます。Future Simple（will）や現在形でも文脈から意味は推測してもらえます。しかし、特にビジネスや契約、詳細な計画を話す際には、未来完了形を使わないと「いつ終わるのか」と「いつまでに終わっているのか」の区別が曖昧になり、誤解を招く可能性があります。中級以上の学習者としては、ぜひ使いこなしたい表現です。will have + 過去分詞という形に慣れないかもしれませんが、by（期限）を見つけたら「未来完了形の出番だ！」と意識することから始めてみてください。この時制が使えるようになると、あなたの英語の「時間感覚」は格段に鋭くなります。頑張りましょう（頑張ってください）！Conjugating 'To Finish' in Future Perfect
| Subject | Auxiliary | Perfective | Past Participle |
|---|---|---|---|
|
I
|
will
|
have
|
finished
|
|
You
|
will
|
have
|
finished
|
|
He/She/It
|
will
|
have
|
finished
|
|
We
|
will
|
have
|
finished
|
|
They
|
will
|
have
|
finished
|
Contractions in the Future Perfect
| Full Form | Contraction | Negative Contraction |
|---|---|---|
|
I will have
|
I'll have
|
I won't have
|
|
You will have
|
You'll have
|
You won't have
|
|
He will have
|
He'll have
|
He won't have
|
|
She will have
|
She'll have
|
She won't have
|
|
It will have
|
It'll have
|
It won't have
|
|
We will have
|
We'll have
|
We won't have
|
|
They will have
|
They'll have
|
They won't have
|
Meanings
Used to express an action that will be completed between now and a specific point in the future.
Future Completion
An action that is finished before another action or time in the future.
“I will have finished the report by 5 PM.”
“They will have arrived before the party starts.”
Duration in the Future
To show how long an action has been happening at a specific point in the future (usually with stative verbs).
“By next Monday, I will have been in this job for ten years.”
“They will have been married for fifty years this June.”
Logical Assumption (Past)
To express a strong belief or certainty that something happened in the past (similar to 'must have').
“You will have heard the news already, I assume.”
“He will have forgotten about the meeting by now.”
Reference Table
| タイプ | 構造 | 例 | 主な特徴 |
|---|---|---|---|
|
肯定文
|
Subject + will have + Past Participle
|
I will have finished
|
未来までに完了する行動
|
|
否定文
|
Subject + will not have + Past Participle
|
She won't have arrived
|
未来までに完了しない行動
|
|
疑問文
|
Will + Subject + have + Past Participle?
|
Will they have eaten?
|
未来の完了を尋ねる
|
|
肯定の短縮形
|
Subject + 'll have + Past Participle
|
You'll have studied
|
インフォーマルな口語英語
|
|
否定の短縮形
|
Subject + won't have + Past Participle
|
We won't have left
|
インフォーマルな否定形
|
フォーマル度スペクトル
The committee will have finalized the proposal by Friday. (Workplace productivity)
I will have finished the report by the end of the day. (Workplace productivity)
I'll have it done by tonight. (Workplace productivity)
I'll have it knocked out by 5. (Workplace productivity)
未来完了形：一目でわかる
構造
- will + have + Past Participle will + have + 過去分詞
- Always 'have', never 'has' after 'will' will の後には必ず 'have'、'has' は使いません
- Contractions 短縮形
- 'I'll have', 'won't have' 'I'll have'、'won't have'
主な使い方
- Future Deadline 未来の締め切り
- By 2025, I will have graduated. By 2025, I will have graduated.
- Before Future Event 未来の出来事の前に
- When you arrive, I will have cooked. When you arrive, I will have cooked.
時間を示す言葉
- by by
- By next week, by 7 PM By next week, by 7 PM
- before before
- Before he leaves Before he leaves
- when when
- When she calls When she calls
よくある落とし穴
- Using 'has' 'has' を使う
- Incorrect: She will has done. 間違い: She will has done.
- Wrong participle 間違った過去分詞
- Incorrect: I will have write. 間違い: I will have write.
未来時制：いつどれを使う？
未来完了形はあなたに合っている？
未来に起こる行動について話していますか？
この行動は、未来の特定の時間や別の出来事までに「完了して」いますか？
この行動は、未来の特定の時間で「進行中」ですか？
状況に応じた未来完了形
計画と締め切り
- • By Friday, I will have finished.
- • The report will have been submitted.
予測と期待
- • He will have heard the news.
- • She'll have seen my story.
出来事の順序付け
- • When you arrive, I will have cooked.
- • Before sunrise, preparations will have been completed.
未来の時点までの期間
- • By December, I will have worked here for a year.
- • We'll have lived here for five years.
レベル別の例文
By 6:00, I will have finished.
By 6:00, I will have finished.
I will have eaten by then.
I will have eaten by then.
Will you have finished your homework?
Will you have finished your homework?
She will have gone to bed.
She will have gone to bed.
By next week, we will have moved house.
By next week, we will have moved house.
I won't have finished the book by tomorrow.
I won't have finished the book by tomorrow.
Will they have arrived by dinner time?
Will they have arrived by dinner time?
By noon, he will have cleaned the car.
By noon, he will have cleaned the car.
By the time you read this, I will have left.
By the time you read this, I will have left.
In two years, I will have completed my degree.
In two years, I will have completed my degree.
They will have built the new bridge by 2025.
They will have built the new bridge by 2025.
Will you have saved enough money by summer?
Will you have saved enough money by summer?
By next month, I will have been with the company for five years.
By next month, I will have been with the company for five years.
The movie will have started by the time we get to the cinema.
The movie will have started by the time we get to the cinema.
Won't you have finished your exams by the end of June?
Won't you have finished your exams by the end of June?
By the time she retires, she will have taught thousands of students.
By the time she retires, she will have taught thousands of students.
You will have noticed that the market has shifted recently.
You will have noticed that the market has shifted recently.
By the end of the decade, technology will have transformed our lives.
By the end of the decade, technology will have transformed our lives.
The package will have been delivered by now, surely.
The package will have been delivered by now, surely.
By the time the government acts, the damage will have been done.
By the time the government acts, the damage will have been done.
Doubtless, he will have anticipated our every move.
Doubtless, he will have anticipated our every move.
By the turn of the century, these traditions will have all but vanished.
By the turn of the century, these traditions will have all but vanished.
The architect will have intended for the light to hit the altar at noon.
The architect will have intended for the light to hit the altar at noon.
Should you arrive late, the ceremony will have already concluded.
Should you arrive late, the ceremony will have already concluded.
間違えやすい
Learners use 'will be doing' when they mean the action is finished.
Both use 'have + V3', but one is for the past and one is for the future.
Simple future doesn't emphasize the 'before' relationship.
よくある間違い
By 5:00 I will finish.
By 5:00 I will have finished.
I will have finish.
I will have finished.
He will has finished.
He will have finished.
I will have went.
I will have gone.
By the time he will arrive, I will have finished.
By the time he arrives, I will have finished.
I will have been finished.
I will have finished.
Will have you finished?
Will you have finished?
I will have finished since two hours.
I will have finished in two hours.
I will have finished until 5 PM.
I will have finished by 5 PM.
By next year I will have had a car.
By next year I will have bought a car.
They will have arrived by yesterday.
They will have arrived by now.
文型パターン
By the time ___, I will have ___.
In ___ years' time, she will have ___.
Will you have ___ by ___?
The ___ will have been ___ by ___.
Real World Usage
By this time next year, I will have completed my certification.
We will have migrated all data by the end of the weekend.
We'll have reached the border by sunrise.
This study will have demonstrated the link between the two variables.
I'll have finished my shower in 10 mins, then I can talk.
The company will have doubled its revenue by 2030.
「by」のフレーズに注目！
「have」と「has」を間違えないで！
不規則動詞をマスターしよう
略語のカジュアルな使い方
未来から逆算して考えてみよう
Smart Tips
Use the Future Perfect to describe your expected graduation or certification dates to sound professional.
Check if you are using a stative verb like 'be' or 'live'. If so, Future Perfect is likely needed.
If you forget the V3, use a synonym that is regular. Instead of 'written', use 'completed'.
Always tap your watch. 'By the time' is a trigger for the Future Perfect in the other half of the sentence.
発音
The 'Will Have' Reduction
In natural speech, 'will have' is often reduced to 'wull-uv' or even 'wuv'.
Contraction Stress
When using 'I'll have', the stress is usually on the past participle, not the auxiliary.
Rising-Falling for Statements
By tomorrow, I will have finished ↘
Conveys certainty and completion.
暗記しよう
記憶術
Remember 'W.H.P.' — Will Have Participle. It's the 'What Has Passed' in the future.
視覚的連想
Imagine a finish line in the future. You are standing past the finish line, looking back at the race you just completed. That 'looking back' is the Future Perfect.
Rhyme
By the time the clock strikes ten, I will have put away my pen.
Story
Imagine a robot named 'Will-Have'. Will-Have only talks about things he finishes. 'By tomorrow, I will have cleaned the planet,' he says. He always looks at his watch and then at a completed task.
Word Web
チャレンジ
Write down three things you will have accomplished by the end of this year using 'I will have...'
文化メモ
British speakers use the Future Perfect more frequently as a modal of deduction (e.g., 'You will have seen the news').
Highly common in 'corporate speak' to emphasize accountability and deadlines.
Often shortened significantly in casual speech, sometimes omitting 'have' entirely in very broad accents (though not grammatically correct).
The Future Perfect in English developed from the combination of the modal 'will' (originally meaning 'to want') and the perfect aspect 'have + participle'.
会話のきっかけ
What will you have accomplished by the time you are 50?
By the end of this month, what will you have learned in English?
If you travel to Japan next year, what cities will you have visited by the end of your trip?
By the time the next election happens, what will have changed in your country?
日記のテーマ
よくある間違い
Test Yourself
By Saturday morning, I ___ all my packing for the trip.
Find and fix the mistake:
She will has graduated by next June.
Arrange the words in the correct order:
All words placed
Click words above to build the sentence
Score: /3
練習問題
8 exercisesBy next month, I ___ (finish) my English course.
Which sentence is grammatically correct?
Find and fix the mistake:
By the time you will get here, I will have cooked dinner.
I am going to finish the report before 5 PM.
Match 'I will be working' and 'I will have worked'.
A: Can we meet at 7 PM? B: No, I ___ (not/finish) my gym session by then.
You can use 'has' in the Future Perfect if the subject is 'he' or 'she'.
have / they / by / arrived / will / noon / ?
Score: /8
Practice Bank
12 exercisesWhen you arrive, I ___ the whole apartment.
By her 30th birthday, she ___ around the world.
We won't has finished the project by next Monday.
By the end of the year, I will save enough for a new car.
Choose the correct sentence:
Choose the correct sentence:
Translate into English: 'Para el próximo mes, habré leído tres libros.'
Translate into English: 'Cuando llegue ella, la cena estará lista.' (Focus on completion by arrival)
Arrange these words into a sentence:
Arrange these words into a sentence:
Match the phrases:
Match the questions:
Score: /12
よくある質問 (8)
In casual speech, yes, but it changes the meaning. `I will finish` means you start finishing at that time. `I will have finished` means it is already done.
This is a rule for all future time clauses (when, before, after, by the time). We use the present tense to refer to the future in these specific clauses.
Not always. It can be the Future Perfect of the verb 'to be' (e.g., `I will have been here for an hour`). It is only passive if followed by another past participle.
It is moderately common. You'll use it most when talking about work deadlines, travel arrivals, or life milestones.
`By` is for a deadline (one point in time). `Until` is for a duration (an action that continues up to a point). You use `by` with Future Perfect.
Yes, but it is very formal and mostly used in British English with 'I' or 'We'. `I shall have finished` is correct but rare.
Most verbs are regular and end in `-ed`. For irregulars, you must memorize the third column of the verb table (e.g., go-went-`gone`).
Yes, in reported speech or conditional sentences (e.g., `He said he would have finished`). This is the 'Future in the Past'.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Futuro Compuesto (Habré cantado)
Spanish uses it more frequently for probability in the present/past.
Futur Antérieur (J'aurai fini)
French requires 'être' for certain verbs of motion, whereas English always uses 'have'.
Futur II (Ich werde abgeschlossen haben)
German speakers usually replace it with the 'Perfekt' (Present Perfect) for simplicity.
〜てしまっているだろう (~te shimatte iru darou)
Japanese relies on context and aspect rather than a dedicated future perfect tense.
سيكون قد (Sa-yakunu qad...)
The particle 'qad' is essential to signal the completion aspect.
已经...了 (Yǐjīng...le)
Meaning is entirely derived from time words (e.g., 'Tomorrow I already finish').
Learning Path
Prerequisites
Learn These First
関連動画
08:07 What’s the best way to give a presentation?
Learn All 12 English Verb Tenses | Complete English Grammar Lesson
JForrest English
MASTER ENGLISH VERB TENSES — All 12 Tenses Explained in 20 Minutes (Complete Guide)
English At The Ready
English Verb Tenses Guide - Learn About Simple, Perfect, and Continuous Tenses
Oxford Online English
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