Master the First Conditional: Talk About Real Future Possibilities (B1 English Grammar) — B1 English grammar lesson by Langcom

Master the First Conditional: Talk About Real Future Possibilities (B1 English Grammar)

ラウル・マグイニャ

Langcom 創設者 | ケンブリッジおよびSIELE試験の試験官

9月 10, 2026

B1✏️ 文法⏱️ 読了時間:5分📅 Updated 9月 2026
The First Conditional helps you talk about real possibilities in the future. We use it to describe situations that are likely to happen if a certain condition is met. For example, If it rains, I will stay home. This sentence means that if the rain happens (a real possibility), then staying home is the likely result. The basic structure is If + present simple, will + base form of verb. It is essential for making plans, giving warnings, or discussing the probable consequences of actions. You can also reverse the clauses, like I will stay home if it rains. This conditional is very common in everyday conversations and useful for expressing cause and effect for future events.

What is the First Conditional?

The First Conditional is a grammar structure we use to talk about things that might happen in the future. It describes a possible condition and its likely result.

  • It’s for situations that are real or very probable.
  • It connects a condition (the ‘if’ part) with a consequence (the main part).

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How Do We Form the First Conditional?

The basic structure of the First Conditional is simple:

  • The 'if' clause: We use the present simple tense. This part states the condition.
  • The main clause (result): 当社では will + base form of the verb. This part states the likely result.

Look at this pattern:

If + present simple, will + base form of verb.

For example:

  • If I study hard, I will pass the exam.
  • If she calls me, I will tell her the news.

When Do We Use the First Conditional?

We use the First Conditional for several purposes related to future possibilities:

  • To talk about real possibilities: Things that are likely to happen. For example, If the weather is good tomorrow, we will go to the beach.
  • To make predictions: Based on current information or beliefs. For example, If he doesn't train, he won't win the race.
  • To give warnings or advice: About potential future problems. For example, If you touch that, you will burn your hand!
  • To make promises or offers: Related to a future action. For example, If you help me, I will buy you dinner.

Comma Rules for the First Conditional

The position of the 'if' clause affects whether you need a comma:

  • If the 'if' clause comes first: Use a comma to separate the two clauses. For example, If it rains, we will stay inside.
  • If the main clause comes first: Do not use a comma. For example, We will stay inside if it rains.

Variations in the First Conditional

一方で will is common, you can use other words in the main clause:

  • Other modal verbs: 使用方法 can, may, might, 、または should to express different levels of certainty or possibility.
    • If you finish your homework, you can watch TV. (permission/ability)
    • If it's sunny, we might go for a walk. (less certainty)
    • If you feel sick, you should see a doctor. (advice)
  • Imperative: Use an imperative (a command) in the main clause. This is common for instructions or warnings.
    • If you see John, tell him to call me.
    • If you are hungry, eat something.
  • Other conjunctions: You can use words like when, as soon as, unless, 、または in case ~の代わりに if.
    • When I arrive, I'll call you.
    • Unless it stops raining, we won't go out. (meaning 'if it doesn't stop')
First Conditional Structure and Examples
Clause Type Structure
If Clause (Condition) If + Present Simple If I have time...
Main Clause (Result) will + Base Form ...I will visit you.
Full Sentence If + Present Simple, will + Base Form If I have time, I will visit you.
Reversed Sentence will + Base Form if + Present Simple I will visit you if I have time.

  • If you study, you will learn a lot.
  • She will be happy if she gets the job.
  • If it snows tomorrow, we won't go to school.
  • They might miss the bus if they don't hurry.
  • If you need help, ask me.
  • I will buy a new car when I save enough money.

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スペイン語話者がよく犯す間違い

Spanish speakers often make a common mistake by using will in the 'if' clause. Remember, in English, the 'if' clause always uses the present simple, even though it refers to a future event.

  • 誤り: If I will go to the party, I will see my friends.
  • 正しい: If I go to the party, I will see my friends.

Another mistake is forgetting the comma when the 'if' clause starts the sentence:

  • 誤り: If it's cold I'll wear a jacket.
  • 正しい: If it's cold, I'll wear a jacket.

よくある質問

What is the main difference between the First Conditional and the Zero Conditional?

The Zero Conditional talks about general truths or facts, things that always happen if a condition is met (e.g., If you heat ice, it melts.). The First Conditional talks about specific, real possibilities in the future (e.g., If it's hot tomorrow, I'll go swimming.).

Can I use 'going to' instead of 'will' in the main clause?

はい、ご利用いただけます be going to in the main clause to express a future intention or a prediction based on present evidence. For example, If I get a promotion, I'm going to buy a new car.

Is the First Conditional important for B1 English exams?

Yes, understanding and correctly using the First Conditional is very important for B1 level exams. You might need it for writing tasks, speaking about future plans, or understanding texts that discuss future possibilities and consequences.

Can I use 'unless' in the First Conditional?

はい、, unless means 'if not'. It introduces a negative condition. For example, Unless you study, you won't pass the exam means the same as If you don't study, you won't pass the exam.

関連レッスン

著者について:ラウル・マグイニャ

ラウル・マグイニャ氏は、認定Cambridge English試験対策センターである「Asociación Educativa Langcom」の所長であり、 あなたの国. 。語学教育および国際資格認定の分野で10年以上の経験を持ち、25カ国にわたる数千人の学生、教師、教育機関が、ケンブリッジ英語検定、IELTS、TOEFL、およびMichiganの英語資格を取得できるよう支援してきました。.

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