First Conditional

Use the First Conditional for real and possible future situations. The condition is stated in the present simple; the result clause typically uses will + base verb (or another modal) to show future outcome, promise or warning.

Formula

If + present simple → will + base verb

When do we use it?

Predictions & expectations: If it rains tomorrow, we will stay inside.
Promises & offers: If you need help, I’ll lend you my notes.
Warnings & threats: If you touch that wire, you’ll get a shock.
Bargains & incentives: If they finish early, the boss will buy pizza.
Instructions with an imperative main clause: If the timer beeps, turn off the oven.

Syntax details

Swap the clauses:

If he calls, I will answer.
I will answer if he calls.

Remember the comma only when the if-clause comes first.

You can replace will with other modals for nuance:
can (ability), may/might (possibility), should (advice).

Affirmative, Negative & Question

Form	Structure	Example
Affirmative	`If + V₁ … , will + base`	If they arrive late, we will start without them.
Negative	`If + do not V₁ … , will not + base`	If she doesn’t finish on time, she won’t catch the train.
Question	`What will + S + do if + S + V₁ … ?`	What will you do if the exam is postponed?

More examples

If I see Anna, I’ll give her your message.
If traffic is heavy, we might be late.
If you mix red and yellow, you’ll get orange.
If they don’t reply today, we’ll call them tomorrow.
If you study hard, you’ll pass the test.
If the shop is closed, I’ll buy snacks elsewhere.
If we leave now, we can catch the early train.
If you press this button, the computer will shut down.
If her flight is delayed, she’ll text us.
If the weather improves, we’ll go hiking this afternoon.

Common mistakes

❌ If it will rain later, we will cancel.
✅ If it rains later, we will cancel.
(No will in the if-clause.)
❌ If I would win the lottery, I will travel.
✅ If I win the lottery, I will travel.
(Use simple present in the condition.)
❌ I will stay home, if it rains.
✅ I will stay home if it rains.
(No comma when the if-clause is last.)
❌ If you study, you can pass. (Not wrong, but weaker.)
✅ If you study, you will pass.
(Choose the modal that matches your meaning.)