Grammar Rule in 30 Seconds
The Future Perfect Continuous describes an ongoing action that will continue up until a specific point in the future, emphasizing its duration.
- Use 'will have been' plus the '-ing' form of the verb for all subjects.
- Always include a time reference like 'by then' or 'for five hours' to provide context.
- Never use stative verbs like 'know' or 'want' in this continuous form; use Future Perfect instead.
Overview
Future Perfect Continuous（未来完了進行形）です。この時制は、ある未来の時点を基準にして、「その時まで、ある動作がどのくらいの期間継続しているか」を表現します。日本語には「〜していることになるだろう」という表現はありますが、英語のような厳密な時制のシステムは存在しません。日本語では単に「〜で3年働いていることになる」のように、文脈で未来の継続を補完しますが、英語では will have been -ing という形式を使って、その「継続性」と「未来の視点」を明示的に構築します。この時制は、単なる事実の伝達ではなく、時間の流れを俯瞰する高度な視点を必要とします。C2レベルを目指す学習者にとって、この時制を使いこなすことは、複雑な計画や予測を論理的かつ洗練された形で伝えるための必須スキルです。特にビジネスの文脈や、長期的なプロジェクトの進捗を語る際、この時制を使うことで「単に終わる」だけでなく「いかに継続してきたかというプロセス」を強調でき、相手に深い納得感を与えることができます。Future Perfect Continuous の本質は、「未来のある時点を観測地点として、そこから過去を振り返り、継続している動作の蓄積を測定する」という点にあります。日本語の文法で言えば、「完了」と「進行」を未来というフィルターに通す作業です。例えば、「来月で、この会社で10年働いていることになる」という文を考えてみましょう。日本語では「働いている」という現在進行の形が未来の文脈でも使われますが、英語では I will have been working here for ten years by next month となります。ここで重要なのは have been の部分です。これは Perfect Aspect（完了相）と Continuous Aspect（進行相）の融合であり、英語特有の「時間の広がり」を捉える感覚です。日本語の「〜ことになる」は、単なる予測や決定事項を表すことが多いですが、英語のこの形は「その時点に至るまでの時間の積み重ね」に焦点が当たっています。日本語の動詞には「完了」と「進行」を分ける専用の時制構造がありません。そのため、英語のこの形を使う際は、頭の中で「未来の時計」をセットし、そこから過去へ向かって時間を遡るという「時空的な視点」を意識する必要があります。この感覚は、日本語の「〜ている」という状態表現を、英語の「時制の網」の中に正確に配置する訓練とも言えます。Future Perfect Continuous の構築は非常に規則的です。以下の表で構成要素を確認しましょう。I, You, The team |will | 未来の予測・意志 | will |have | 完了の起点 | have |been | 進行の継続 | been |-ing | 動作の性質 | working, studying |Subject + will + have + been + verb-ingSubject + will + not + have + been + verb-ingWill + Subject + have + been + verb-ing?he/she/it であっても、have は決して has にはならないという点です。これは will という助動詞の後ろにあるため、必ず不定詞の have が来るという英語の文法ルールに基づいています。ここを間違えると、非常に不自然に聞こえます。- 1未来の時点までの期間を強調する: 「来年で30年になる」といった期間の長さを強調したい場合です。
By the time I retire, I will have been writing code for 20 years.（退職する時までに、私は20年間コードを書き続けていることになる。） - 2未来の事態の原因を説明する: 未来のある状態が、それまでの継続的な行動の結果であることを示す場合です。
She will be exhausted because she will have been traveling for 24 hours.（彼女は24時間移動し続けていることになるので、疲れ切っているだろう。） - 3仮定法的な未来のシミュレーション: 「もし〜なら、その時は〜しているはずだ」という予測です。
If we keep this pace, by Friday we will have been working on this project for a month.（もしこのペースを維持すれば、金曜日までにはこのプロジェクトに1ヶ月取り組んでいることになる。）
- 1状態動詞（Stative Verbs）の使用: 日本語では「ずっと知っている」「ずっと持っている」を進行形で表現することが多いため、英語でも
I will have been knowing him for 5 yearsと言いがちです。しかし、knowやownなどの状態動詞は進行形にできません。正しくはI will have known him for 5 yearsと、未来完了形（Simple）を使います。 - 2「完了」と「継続」の混同:
By 5 PM, I will have been finished my work.と言ってしまうミスです。finishは「一瞬で終わる」動作であり、継続には不向きです。正しくはI will have finished my workです。日本語の「終わっている」という状態に引きずられ、進行形を無理やり当てはめてしまうのが原因です。 - 3時制の重複:
When I will arrive, I will have been waiting.と言ってしまうミスです。when節の中では未来形を使わず、現在形にするのが英語のルールです。正しくはWhen I arrive, I will have been waiting for an hour.です。
I will have finished. | I will have been working. |- 1Q: なぜ
will have beenで止まるのですか？
will（未来）+ have（完了）+ been（進行の土台）という順序で、各時制要素が積み重なっているからです。この順序は固定です。- 1Q: 状態動詞を進行形にするとどうなりますか？
continuous（進行）と相性が悪いのです。- 1Q: 実際の会話で頻繁に使われますか？
Conjugating 'To Work' in Future Perfect Continuous
| Subject | Auxiliary | Perfect/Continuous Markers | Verb Form |
|---|---|---|---|
|
I
|
will
|
have been
|
working
|
|
You
|
will
|
have been
|
working
|
|
He/She/It
|
will
|
have been
|
working
|
|
We
|
will
|
have been
|
working
|
|
They
|
will
|
have been
|
working
|
|
I (Negative)
|
will not (won't)
|
have been
|
working
|
|
He (Question)
|
Will [he]
|
have been
|
working?
|
Common Contractions
| Full Form | Contraction | Pronunciation Hint |
|---|---|---|
|
I will have been
|
I'll've been
|
Ayl-uv-bin
|
|
You will have been
|
You'll've been
|
Yool-uv-bin
|
|
He will have been
|
He'll've been
|
Heel-uv-bin
|
|
They will have been
|
They'll've been
|
Thayl-uv-bin
|
|
Will not have been
|
Won't've been
|
Wont-uv-bin
|
Meanings
Used to project ourselves forward in time and look back at the duration of an activity that is still in progress at that future point.
Duration up to a future point
Emphasizing how long an action has been happening before a specific deadline or event in the future.
“By the time the guests arrive, she will have been cooking for six hours.”
“In December, they will have been dating for five years.”
Cause of a future result
Using the duration of a future action to explain a future state or result.
“I'll be exhausted when I see you because I will have been driving all day.”
“Her English will be perfect because she will have been studying in Oxford for two years.”
Interrupted future action
Describing an ongoing future action that is interrupted by another shorter action.
“Will you have been sleeping for long when the alarm goes off?”
“They will have been playing for hours by the time we join them.”
Reference Table
| 機能 | 構造 | 例文 | 焦点 |
|---|---|---|---|
|
未来の時点までの継続期間
|
`will have been + V-ing`
|
By 5 PM, she will have been studying for three hours.
|
5時までの「時間の長さ」
|
|
未来の因果関係
|
`will have been + V-ing`
|
He'll be tired because he will have been jogging all morning.
|
未来の疲れの「原因」
|
|
進行中の活動の予測
|
`will have been + V-ing`
|
They will have been traveling for days when they arrive.
|
到着時の「旅の継続期間」
|
|
否定形
|
`won't have been + V-ing`
|
She won't have been sleeping much by then.
|
継続期間の「否定」
|
|
疑問形
|
`Will + S + have been + V-ing?`
|
Will you have been waiting long?
|
継続期間への「問い」
|
フォーマル度スペクトル
By the conclusion of this fiscal year, I shall have been serving as Director for a decade. (Work anniversary)
By the end of the year, I will have been working as Director for ten years. (Work anniversary)
I'll have been the boss here for ten years come December. (Work anniversary)
I'll have been running this show for ten years straight by New Year's. (Work anniversary)
未来完了進行形：期間の旅路
核となるアイデア
- 継続期間 How long?
- 未来の時点 By when?
構成要素
- Will 未来の助動詞
- Have Been 完了進行の助動詞
- Verb-ing 現在分詞
主な用途
- 原因と結果 Future reason
- 予測 Ongoing activity
未来の時制比較：進行 vs 完了 vs 完了進行
未来の時制選びフローチャート
未来の時点でその動作は進行中ですか？
未来の時点までにその動作は完了しますか？
未来の時点までの「期間の長さ」を強調したいですか？
未来完了進行形：文脈とヒント
タイムマーカー
- • By next week
- • When you arrive
- • For X hours
- • Since X date
表現される感情
- • 疲労困憊
- • 期待感
- • 安堵
- • もどかしさ
よくある場面
- • 長期プロジェクト
- • 待ち時間の説明
- • スキルの習得期間
- • 未来の習慣
避けるべき場合
- • 状態動詞
- • 一瞬で終わる動作
- • 単なる完了の報告
レベル別の例文
By next year, I will have been living here for a long time.
By next year, I will have been living here for a long time.
In June, she will have been working for two months.
In June, she will have been working for two months.
By 6 PM, they will have been playing for one hour.
By 6 PM, they will have been playing for one hour.
Will you have been waiting for long?
Will you have been waiting for long?
By the time you wake up, I will have been driving for hours.
By the time you wake up, I will have been driving for hours.
She won't have been studying for long when the test starts.
She won't have been studying for long when the test starts.
How long will they have been traveling by next week?
How long will they have been traveling by next week?
By dinner, we will have been cooking for three hours.
By dinner, we will have been cooking for three hours.
By the end of the semester, I will have been attending this course for fifteen weeks.
By the end of the semester, I will have been attending this course for fifteen weeks.
They will have been renovating the house for a year by the time they move in.
They will have been renovating the house for a year by the time they move in.
Will the team have been practicing enough before the big game?
Will the team have been practicing enough before the big game?
I won't have been living in this city for very long when I start my new job.
I won't have been living in this city for very long when I start my new job.
By the time the sun sets, the hikers will have been climbing for over eight hours.
By the time the sun sets, the hikers will have been climbing for over eight hours.
She will have been practicing the piano for a decade by her next recital.
She will have been practicing the piano for a decade by her next recital.
Will you have been working on that project for long when the deadline arrives?
Will you have been working on that project for long when the deadline arrives?
The researchers will have been collecting data for months before they publish the results.
The researchers will have been collecting data for months before they publish the results.
By the time the treaty is signed, the diplomats will have been negotiating for nearly three years.
By the time the treaty is signed, the diplomats will have been negotiating for nearly three years.
The engine will have been running for several hours by the time we reach the border.
The engine will have been running for several hours by the time we reach the border.
I suspect they will have been anticipating this announcement for quite some time.
I suspect they will have been anticipating this announcement for quite some time.
Won't you have been feeling a bit overwhelmed by the time the conference concludes?
Won't you have been feeling a bit overwhelmed by the time the conference concludes?
By the time the spacecraft reaches Mars, it will have been hurtling through the void for seven months.
By the time the spacecraft reaches Mars, it will have been hurtling through the void for seven months.
The philosopher will have been contemplating the nature of existence for half a century by the time his magnum opus is released.
The philosopher will have been contemplating the nature of existence for half a century by the time his magnum opus is released.
Should the strike continue, the factory will have been standing idle for the better part of a year.
Should the strike continue, the factory will have been standing idle for the better part of a year.
By the time the jury returns a verdict, the defendant will have been languishing in uncertainty for weeks.
By the time the jury returns a verdict, the defendant will have been languishing in uncertainty for weeks.
間違えやすい
Learners mix up completion and duration. They use Simple when they want to emphasize the 'how long'.
Both describe ongoing actions in the future, but one measures from a start point.
Learners use this when they should project into the future.
よくある間違い
I will been working.
I will have been working.
I will have being working.
I will have been working.
By tomorrow, I will working.
By tomorrow, I will have been working.
I will have been work.
I will have been working.
By the time he will come, I will have been waiting.
By the time he comes, I will have been waiting.
She will has been studying.
She will have been studying.
Will have you been waiting?
Will you have been waiting?
I will have been knowing her for years.
I will have known her for years.
By next year, I will have been being a teacher.
By next year, I will have been a teacher.
I will have been working since 5 hours.
I will have been working for 5 hours.
By the time the sun will have set, we will have been driving.
By the time the sun sets, we will have been driving.
I will have been finishing the book by then.
I will have finished the book by then.
They will have been wanting to leave.
They will have wanted to leave.
文型パターン
By the time ___, I will have been ___ for ___.
In ___, they will have been ___ since ___.
Will you have been ___ for long when ___?
She won't have been ___ for more than ___ by ___.
Real World Usage
By next July, I will have been working in project management for a decade.
By tonight, we will have been married for fifty years!
By the time we land, we will have been flying for fifteen hours.
The sample will have been incubating for 48 hours by the time we check it.
By the end of this workout, I'll have been lifting for two hours straight! #beastmode
By the time the bridge opens, they will have been building it for five years.
'By' と 'For' を探そう
By next year, I will have been learning English for five years.
状態動詞に注意！
By then, I will have known him for a long time.
「未来の感情」を乗せる
ネイティブの直感
She will have been researching this topic for years by the time she publishes her book.
「道のり」が主役
When the marathon ends, they will have been running for four hours.
Smart Tips
Use the Future Perfect Continuous to emphasize your patience.
Use this tense to project your experience into the future for a potential employer.
Check if there is a 'have been' in the middle. If not, it's just Future Continuous.
Freeze! Don't use 'will' in that specific part of the sentence.
発音
The 'Have' Reduction
In natural speech, 'have' is reduced to a short /əv/ sound, often sounding like 'of'.
The 'Been' Reduction
The word 'been' is usually unstressed and pronounced with a short /ɪ/ like 'bin'.
Contraction Stress
The stress usually falls on the main verb (-ing), not the auxiliaries.
Emphasis on Duration
I will have been waiting for FIVE hours! (Rising intonation on 'five')
Expressing frustration or highlighting the length of time.
暗記しよう
記憶術
W.H.B.I: Will Have Been -Ing. Think: 'Will He Be Interesting?' to remember the order.
視覚的連想
Imagine a long, glowing bridge stretching from today into next year. On the bridge, you are running. At the end of the bridge is a giant clock. The bridge is the 'duration', and the clock is the 'future point'.
Rhyme
By the time the clock strikes ten, I will have been working since way back when.
Story
A marathon runner is training. By the time the race starts in November, she will have been training for six months. She will have been running 50 miles a week. This story links the future event (the race) with the long effort leading up to it.
Word Web
チャレンジ
Look at your watch. Imagine it is 5 hours from now. Write one sentence about what you will have been doing for those 5 hours.
文化メモ
This tense is often used to politely emphasize one's effort or patience in professional settings.
The use of 'shall' instead of 'will' is still occasionally found in very formal British legal or academic writing, though it's fading.
Americans often simplify this to the Future Continuous or Future Perfect Simple in casual speech, reserving the Continuous Perfect for high emphasis.
The English perfect continuous is a relatively late development in the Germanic family, evolving from the need to express both aspect (ongoingness) and tense (time).
会話のきっかけ
By the end of this year, how long will you have been studying English?
If you stay in your current job for another two years, how long will you have been working there in total?
By the time you go to bed tonight, what will you have been doing all day?
Imagine your dream vacation. By the time it ends, how long will you have been traveling?
日記のテーマ
よくある間違い
Test Yourself
By 10 PM, I ___ for five hours straight.
Find and fix the mistake:
When the boss arrives, we will have been finished the report for three hours.
Choose the correct sentence:
Translate into English: 'Para el próximo año, habrán estado viajando por el mundo durante seis meses.'
Answer starts with: ["B...
Score: /4
練習問題
8 exercisesBy next month, I ___ (live) in this apartment for exactly three years.
Select the correct option:
Find and fix the mistake:
By the end of the day, he will have been knowing the truth for five hours.
I started studying at 2 PM. It is now 4 PM. By 5 PM, how long is the duration?
You can use the Future Perfect Continuous with the verb 'to be'.
A: You look like you'll be exhausted tomorrow. B: I will! By the time I see you, I ___ all night.
Select the stative verb:
Match the following:
Score: /8
Practice Bank
13 exercisesBy the time the movie ends, I ___ for over two hours.
At midnight, he will have been sleep for six hours.
Choose the correct sentence:
Translate into English: '退職する時までに、その医師は40年以上医学に携わってきたことになります。'
単語を並べ替えて正しい文を作ってください：
主語と正しい動詞の形を組み合わせてください：
When the deadline hits, I ___ on this presentation for a week.
Tomorrow morning, by 9 AM, the birds will has been singing since dawn.
正しい文はどれですか？
Translate into English: '私たちが到着する頃には、彼らは2時間待ち続けていることになります。'
単語を並べ替えてください：
文を完成させてください：
By next month, I ___ at this company for exactly twenty years.
Score: /13
よくある質問 (8)
It is less common than the `Future Simple`, but very common when people talk about work milestones, anniversaries, or travel durations. It adds a specific 'flavor' of duration that other tenses lack.
Yes, but only with 'I' or 'We' (e.g., `I shall have been working`). It sounds very formal and is mostly used in British English or legal documents.
The `Future Continuous` (`I will be working`) just means you are in the middle of an action at a future time. The `Future Perfect Continuous` (`I will have been working for 2 hours`) measures how long that action has been happening.
Because `know` is a stative verb. Stative verbs describe states, not actions, so they don't have a 'continuous' aspect. Use `I will have known` instead.
Almost always. Without a duration marker, the tense feels 'empty' because its primary purpose is to measure time.
Technically yes (`The car will have been being repaired`), but it is so clumsy that even native speakers avoid it. Use the `Future Perfect Simple Passive` instead.
The sentence becomes ungrammatical. `I will have working` doesn't exist in English. You need the `been` to link the perfect and continuous aspects.
No, you can use 'When', 'By [Date]', 'In [Duration]', or 'Before'. Just remember the Present Simple rule for the 'When/Before' clauses!
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Habrá estado trabajando
Spanish often uses 'llevar' to express duration instead of the perfect continuous.
Futur Antérieur + en train de
French focuses on completion rather than duration in the future.
Futur II
German uses the present tense for future duration: 'Nächstes Jahr arbeite ich hier schon zehn Jahre'.
~te iru koto ni naru
Japanese relies on context and time adverbs rather than complex verb conjugation.
sa-yakunu qad istamarra
Arabic uses a 'particle + auxiliary' system that is structurally distinct from English.
yǐjīng ... le
Chinese is an isolating language; it uses zero verb changes.
Learning Path
Prerequisites
関連動画
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