B1 · Intermediate TOEIC 405–600 IELTS 4.0–5.0 Clauses & Conditionals

First Conditional

If + present simple, will + infinitive — for real and likely future situations.

What is the First Conditional?

We use the first conditional to talk about a real and possible situation in the future. It describes a likely outcome that will happen if a certain condition is met.

Think of it as "Cause and Effect" for the future. If A happens, then B will happen.

  • If it rains tomorrow, I will take an umbrella.
    (Condition: rain is a real possibility. Result: taking an umbrella is the likely outcome.)

The Structure

The first conditional has two parts: the if-clause (the condition) and the main clause (the result).

Standard Formula:

If + Present Simple, ... will + Base Verb

If-Clause (Condition) Main Clause (Result)
If I see John, I will tell him the news.
If you study hard, you will pass the exam.
If they don't hurry, they will miss the train.

Remember: When the if-clause comes first, you must use a comma to separate the clauses.

Reversed Formula:

You can also switch the order of the clauses. No comma is needed in this case.

Will + Base Verb ... if + Present Simple

  • I will tell John the news if I see him.
  • You will pass the exam if you study hard.
  • They will miss the train if they don't hurry.

Using Modals Other Than "Will"

While "will" is the most common verb in the main clause, you can use other modal verbs to change the meaning slightly.

Modal Meaning Example
can Ability / Possibility If we save enough money, we can buy a new car.
may / might Possibility (less certain than 'will') If the weather is nice, we may go to the beach.
should Advice If you want to be healthy, you should eat more vegetables.
must Obligation If you want to enter the building, you must show your ID.

Common Errors and How to Fix Them

The most common mistake is using "will" in the if-clause. Never do this.

✗ Incorrect ✓ Correct Why
If I will see him, I'll tell him. If I see him, I'll tell him. The if-clause always uses the Present Simple for a future condition.
If you will be late, please call me. If you are late, please call me. Use the present tense of "to be" (am/is/are) in the if-clause.
I'll call you if I will finish early. I'll call you if I finish early. The rule applies even when the if-clause is second.
If she study, she will pass. If she studies, she will pass. Remember to use the correct Present Simple form (add -s for he/she/it).

First vs. Zero Conditional

Type Use Example
Zero Conditional General truths and facts (always true). If you heat ice, it melts.
First Conditional A specific, possible future situation. If you heat the soup, it will be ready for lunch.

Summary

Structure Use Comma? Example
If + Pres. Simple, will + Verb A real possibility in the future. Yes If it's sunny, we'll go out.
Will + Verb + if + Pres. Simple A real possibility in the future. No We'll go out if it's sunny.

💡 The key takeaway: Use the First Conditional for a specific future plan or possibility. Remember the simple rule: No "will" in the "if" part!