Grammar Rule in 30 Seconds
Use the Zero Conditional to talk about things that are always true, like scientific facts or personal habits.
- Use Present Simple in both clauses for facts: 'If you heat ice, it melts.'
- Use 'When' instead of 'If' when the situation is certain to happen.
- Never use 'will' in either part of a Zero Conditional sentence.
Overview
if や when にあんなに興奮するのか、不思議に思ったことはありませんか？それは、これらが世界のルールについて語るための基本要素だからです。ゼロ条件句（Zero Conditional）を、言語の「物理法則」と考えてみてください。明日何が起こる「かもしれない」とか、昨日何が起こる「可能性があった」という話ではありません。自然の法則や繰り返される習慣のように、「常に」起こることについての話です。スマホを落とせば、地面に落ちます。（宇宙にいない限りは、ですが）。それほど単純なことなのです。このパターンは、100%確実なことを説明するために使います。コンピュータープログラムの「If/Then（もし〜なら、その時は〜）」ルールを設定するようなものです。これが理解できれば、科学的な事実から自分自身のルーティンまで、あらゆるところにパターンが見えてきます。これは、最も純粋な形での「原因と結果」の文法です。正直なところ、これはあなたの道具箱の中で最も役立つツールの1つです。なぜなら、「たぶん」や「おそらく」といった曖昧さを排除して、物事がどう機能するかを説明できるからです。How This Grammar Works
Formation Pattern
will や would のような凝った助動詞は必要ありません。
If + you heat ice（現在形）, it melts（現在形）.
When To Use It
- 科学的事実： これらは大きな真実です。「赤と青を混ぜると、紫になる」。これは科学であり、反論の余地はありません！
- 個人的な習慣： 自分自身の「プログラミング」を説明するために使います。「起きたら、インスタをチェックする」。これはあなたにとって常に真実である繰り返しのルーティンです。
- 指示とルール： アプリの設定やゲームのルールを考えてみてください。「画面をダブルタップすると、ビデオが一時停止する」。または「信号が赤になると、止まる」。
- 一般的な真実： 社会で一般的に真実として受け入れられていること。「仕事があれば、税金を払う」。（残念ながら、これは非常に現実的な話です）。
Common Mistakes
- 'Will' を足してしまう： これが最も一般的な間違いです！「If it rains, the grass will get wet.」と言いがちですが、これは実は第1条件句（予測）です。ゼロ条件句（一般的な事実）の場合は、単に「If it rains, the grass gets wet.」と言いましょう。
- '-s' を忘れる： 三人称単数を忘れないでください！「ピーナッツを食べると（he eats）、彼は気分が悪くなる（he gets sick）」。それらの小さな文字を見逃さないようにしましょう。
- 'If' と 'When' を混同する： これらは多くの場合入れ替え可能ですが、「when」は何かが「if」よりも頻繁に起こる、またはより確実であることを暗示します。
- 時制を複雑にしすぎる： 「is going to」や「would」は必要ありません。シンプルに現在形でいきましょう！
Contrast With Similar Patterns
- ゼロ条件句： (If + 現在形, 現在形) = 一般的な真実/習慣。「コーヒーを飲むと、目が冴える」。（これは毎回起こることです）。
- 第1条件句： (If + 現在形, Will + 動詞の原形) = 特定の未来の予測。「今このコーヒーを飲んだら、今夜は目が冴えてしまうだろう」。（これは特定の1杯のコーヒーについての話です）。
Quick FAQ
「if」の代わりに「whenever」を使えますか？
もちろんです！「Whenever」を使うと、頻度がより強調されます。「猫を見かけるといつも、撫でようとしてしまう」。
結果の部分に命令形を使っても大丈夫ですか？
はい！指示を出すときには非常によく使われます。「道に迷ったら、電話して」。
節の順序を変えると意味が変わりますか？
いいえ、「if」の部分を最初についても最後に置いても意味は変わりません。カンマのルールだけ覚えておいてくださいね！
過去に起こったことに対してこれを使えますか？
基本的には使いません。ゼロ条件句は、時代を超えて「一般的に」真実であることについてです。過去の習慣には、通常「used to」や過去形を使います。
Zero Conditional Structure
| Clause Type | Conjunction | Subject | Verb Tense | Example |
|---|---|---|---|---|
|
Condition
|
If / When
|
I / You / We / They
|
Present Simple
|
If you heat ice
|
|
Result
|
(comma)
|
It
|
Present Simple
|
it melts
|
|
Negative Condition
|
If
|
He / She / It
|
Does not + Verb
|
If she doesn't study
|
|
Negative Result
|
(comma)
|
She
|
Does not + Verb
|
she fails
|
|
Question
|
Do / Does
|
Subject
|
Verb... if clause
|
Do you cry if you are sad?
|
Common Contractions in Zero Conditional
| Full Form | Contraction | Usage Example |
|---|---|---|
|
do not
|
don't
|
If you don't go, I don't go.
|
|
does not
|
doesn't
|
If it doesn't rain, the grass dies.
|
|
I am
|
I'm
|
If I'm late, they start without me.
|
|
it is
|
it's
|
If it's cold, I wear a coat.
|
Meanings
A sentence structure used to express general truths, scientific facts, and situations where one action always causes another.
Scientific Facts
Describing laws of nature or universal truths that never change.
“If water reaches 100 degrees, it boils.”
“If you drop an object, it falls to the ground.”
Personal Habits & Routines
Describing things you consistently do in response to a specific trigger.
“If I wake up late, I skip breakfast.”
“When I feel stressed, I go for a run.”
Instructions & Rules
Giving commands or explaining how a system works.
“If the light turns red, stop the car.”
“When the bell rings, the lesson ends.”
Reference Table
| 条件文の種類 | 構造 | 目的 | 例文 |
|---|---|---|---|
|
ゼロ条件文
|
If/When + 現在形, 現在形
|
普遍的な事実、一般的な真実
|
If you freeze water, it turns to ice.
|
|
ゼロ条件文 (順序逆)
|
現在形 if/when 現在形
|
普遍的な事実、一般的な真実
|
Water turns to ice if you freeze it.
|
|
When (確実性)
|
When + 現在形, 現在形
|
予測される、定期的な出来事
|
When I wake up early, I feel energized.
|
|
If (可能性/選択)
|
If + 現在形, 現在形
|
条件は可能性あり、結果は確実
|
If you eat too much, you feel sick.
|
|
よくある間違い
|
If + Simple Present, WILL + Verb
|
未来の予測 (第一条件文)
|
If you heat ice, it *will* melt. (Incorrect)
|
|
正しい形
|
If + Simple Present, Simple Present
|
常に真実の結果
|
If you heat ice, it *melts*. (Correct)
|
フォーマル度スペクトル
If an employee arrives after 9:00 AM, the tardiness is recorded. (Workplace policy)
If you are late for work, you get in trouble. (Workplace policy)
If you're late, the boss gets mad. (Workplace policy)
If you show up late, you're toast. (Workplace policy)
ゼロ条件文：普遍的な事実
構造
- If/When + Simple Present 条件節
- Simple Present 結果節
機能
- Scientific Facts 例：水は凍る
- General Observations 例：人は疲れる
- Irrefutable Truths 例：太陽は昇る
If と When
- If 一般的な可能性、選択
- When 予想される規則性、確実性
ゼロ条件文における If と When の比較
ゼロ条件文の判断フロー
その文は普遍的な事実または常に真実についてですか？
その条件は予想される、または定期的に起こることですか？
両方の節は現在形ですか？
ゼロ条件文のシナリオ
科学的事実
- • If you heat ice, it melts.
- • When water boils, it produces steam.
一般的な観察
- • If people don't eat, they get hungry.
- • When I'm tired, I make mistakes.
個人的な真実/習慣
- • If my phone battery dies, I feel disconnected.
- • When my alarm rings, I get up.
手順の規則
- • If you press 'undo', the last action reverses.
- • When you save, changes apply.
レベル別の例文
If I am tired, I sleep.
If I am tired, I sleep.
If you heat water, it is hot.
If you heat water, it is hot.
When it rains, I stay home.
When it rains, I stay home.
If I see her, I say hello.
If I see her, I say hello.
If you don't eat, you get hungry.
If you don't eat, you get hungry.
When the sun goes down, it gets dark.
When the sun goes down, it gets dark.
If you press this button, the light turns on.
If you press this button, the light turns on.
Does it work if you plug it in?
Does it work if you plug it in?
If you mix oil and water, they don't stay together.
If you mix oil and water, they don't stay together.
When I drink coffee late at night, I can't sleep.
When I drink coffee late at night, I can't sleep.
If a customer complains, we offer a refund.
If a customer complains, we offer a refund.
Unless it rains, I walk to work every day.
Unless it rains, I walk to work every day.
If the temperature drops below zero, water freezes.
If the temperature drops below zero, water freezes.
When people exercise regularly, they feel better.
When people exercise regularly, they feel better.
If the economy slows down, unemployment usually rises.
If the economy slows down, unemployment usually rises.
If you don't have a password, you can't access the file.
If you don't have a password, you can't access the file.
If one ignores the symptoms, the condition worsens.
If one ignores the symptoms, the condition worsens.
Whenever the government raises taxes, there is public outcry.
Whenever the government raises taxes, there is public outcry.
If a contract contains an error, it is legally void.
If a contract contains an error, it is legally void.
When a species loses its habitat, it faces extinction.
When a species loses its habitat, it faces extinction.
If power corrupts, absolute power corrupts absolutely.
If power corrupts, absolute power corrupts absolutely.
When the market reaches saturation, innovation becomes the only path to growth.
When the market reaches saturation, innovation becomes the only path to growth.
If a theory fails to account for new data, it is eventually discarded.
If a theory fails to account for new data, it is eventually discarded.
Whenever the artist revisits this theme, the tone remains somber.
Whenever the artist revisits this theme, the tone remains somber.
間違えやすい
Learners use 'will' in Zero Conditional or vice versa. They think all 'if' sentences need 'will'.
Using 'if' for things that are 100% certain to happen (like the sun rising).
Learners forget that 'unless' means 'if... not'.
よくある間違い
If it rain, the grass get wet.
If it rains, the grass gets wet.
If I am hungry I eat.
If I am hungry, I eat.
If you heat ice, it will melt.
If you heat ice, it melts.
When I wake up, I am drinking coffee.
When I wake up, I drink coffee.
If you don't study, you will fail.
If you don't study, you fail.
Does the water boil if you heated it?
Does the water boil if you heat it?
If it is raining, I take an umbrella.
If it rains, I take an umbrella.
If you will mix red and blue, you get purple.
If you mix red and blue, you get purple.
Unless you don't eat, you stay healthy.
Unless you eat, you stay healthy.
When I am seeing him, I feel happy.
When I see him, I feel happy.
If the law will be broken, there is a penalty.
If the law is broken, there is a penalty.
Provided that it will rain, the crops grow.
Provided that it rains, the crops grow.
If one would be late, one is punished.
If one is late, one is punished.
文型パターン
If you ___, you ___.
When it ___, I ___.
___ if you ___.
Whenever ___, ___.
Real World Usage
If the pressure increases, the volume decreases.
If the sauce gets too thick, add a splash of water.
If the red light blinks, replace the battery.
If you work on a holiday, you receive double pay.
If I'm late, just start the movie without me.
If you use the weights, put them back after.
If you don't finish your vegetables, you don't get dessert.
「常に真実」かを考えてみよう
「will」に注意！
「If」と「When」のニュアンス
普遍的な受け入れ
コンマの位置
Smart Tips
Check that both verbs are in the Present Simple. If you see a 'will', delete it!
Use the 'If + Present Simple, Imperative' pattern for clarity.
Swap 'if' for 'when' to sound more natural.
Use 'whenever' instead of 'if' to emphasize that the rule applies every single time.
発音
The Comma Pause
When the 'if' clause comes first, there is a slight rising intonation at the end of the clause, followed by a brief pause.
Contraction Stress
In 'don't' or 'doesn't', the 't' is often unreleased (stopped), but the vowel is stressed to show negation.
Conditional Rise-Fall
If you heat ice ↗, it melts ↘.
The rise indicates the condition is being set; the fall indicates the certain result.
暗記しよう
記憶術
Zero is for Zero Doubt. If it's a fact, keep the tense intact (Present + Present).
視覚的連想
Imagine a light switch. If you flip the switch (Condition), the light turns on (Result). It happens every single time, without fail.
Rhyme
If the truth is what you say, keep the 'will' far away.
Story
A scientist is in a lab. He says: 'If I mix these, it explodes.' He doesn't say 'it will explode' because he has done it 1,000 times and it's a law of nature.
Word Web
チャレンジ
Look around your room. Write 3 Zero Conditional sentences about how things work (e.g., 'If I press the power button, the TV turns on').
文化メモ
British speakers often use 'if' and 'when' interchangeably for habits, but may use 'should' in formal zero-like instructions (e.g., 'Should you require assistance, please ask').
Americans frequently use the Zero Conditional for 'tough love' advice or common sense rules.
In academic papers, the Zero Conditional is the standard for describing methodology and universal results, avoiding 'will' to maintain a timeless, objective tone.
The term 'Zero Conditional' was coined by grammarians in the 20th century to categorize conditional sentences by their degree of probability.
会話のきっかけ
What happens if you don't drink water for a whole day?
What do you usually do when you feel stressed?
Tell me about a rule in your country. What happens if someone breaks it?
If a person wants to be successful in your field, what do they need to do every day?
日記のテーマ
よくある間違い
Test Yourself
If you don't study, you ___ your exams.
Find and fix the mistake:
When it rains, the roads will get slippery.
Choose the correct sentence:
Translate into English: 'Si mezclas rojo y azul, obtienes morado.'
Answer starts with: ["I...
Score: /4
練習問題
8 exercisesIf you ___ (mix) red and white, you ___ (get) pink.
Choose the best option:
Find and fix the mistake:
Correct the sentence:
Rewrite:
We use the Zero Conditional to talk about a specific event in the future.
A: Does this machine work? B: Yes, if you ___ the green button, it ___.
Identify the outlier:
1. If you don't water plants... / 2. If you add sugar... / 3. If you exercise...
Score: /8
Practice Bank
10 exercisesWhen a baby is hungry, it often ___ (cry).
If you touch a hot stove, you will burn your hand.
Which of these is a correct Zero Conditional statement?
Translate into English: 'Si duermas poco, te sientes cansado.'
Arrange these words into a sentence:
Match the conditions with their usual results:
___ you press the 'enter' key, the command executes.
If an object is heavier, it falls faster.
Which sentence is a correct Zero Conditional statement?
Translate into English: 'Wenn man lange vor dem Bildschirm sitzt, tun die Augen weh.'
Score: /10
よくある質問 (8)
Generally, no. If you use `will`, it becomes a First Conditional, which is for specific future events. Zero Conditional is for things that are *always* true.
Use `if` for things that might happen (If it rains...). Use `when` for things you are sure will happen (When the sun sets...).
Only if the `if/when` clause comes first. If it comes second (e.g., 'Ice melts if you heat it'), no comma is needed.
Yes! This is very common for instructions. For example: 'If you are lost, look at the map.'
Yes. `Unless` means 'if not'. Example: 'Plants die unless you water them' is the same as 'Plants die if you don't water them.'
It is neutral. It is used in everything from casual texting to formal scientific journals.
No. If you use the past tense, it usually becomes a Second Conditional (imaginary) or a past habit. Zero Conditional strictly uses the Present Simple.
It's called 'Zero' because there is zero doubt about the result. It is a 100% certainty.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Si + presente, presente
English is stricter about using Present Simple for general truths.
Si + présent, présent
French sometimes uses the future where English requires the present for generalities.
Wenn + Präsens, Präsens
German uses one word ('wenn') for both 'if' and 'when'.
~to (~と)
Japanese has multiple conditional forms (~tara, ~ba, ~to) while English uses one structure with different conjunctions.
Idha (إذا) + Present
Arabic verb aspects (perfective/imperfective) function differently than English tenses.
Ruguo (如果)... jiu (就)...
Lack of tense markers in Chinese makes the 'Present Simple' rule hard for learners to visualize.
Learning Path
Prerequisites
Learn These First
Continue With
関連動画
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