First conditional

First conditional

The Zero Conditional:

(if + present simple, ... present simple)
If you heat water to 100 degrees, it boils.

We use the zero conditional to talk about general truths or results that always happen if a condition is present. We are talking in general, not about one particular situation.

  • If the milk smells bad, I don’t drink it.
  • If water reaches 100 degrees, it boils. 
  • If I’ve drunk, I never drive. 
  • If people are talking all the time, I can’t concentrate. 

If we put the main clause at the beginning, we don’t use a comma between the two clauses.

  • I never go to bed late if I have to get up early. 


We can usually replace the if in this conditional with when without changing the meaning.

  • Dogs can attack you when you are scared. 
  • When the weather is bad, people don’t go shopping. 


The First Conditional:


(if + present simple, ... will + infinitive)
If it rains tomorrow, we'll go to the mall.


If clause and main clause

All conditional sentences have two parts: the if clause and the main clause. It doesn’t matter which clause comes first, but when the if clause comes first, we should put a comma after it.

  • If it rains, we’ll stay home
  • We’ll stay home if it rains.

If + present, future

In the first conditional, the verb in the if clause is present, and the verb in the main clause is future.

  • If you don’t go to sleep, you’ll be very tired tomorrow.


The if clause may have a present or a future meaning, but the verb is always in the present (NOT future)

  • If you will be a good boy tomorrow, mummy will buy you a present. INCORRECT 
  • If you are a good boy tomorrow, mummy will buy you a present. CORRECT

Main clause: will, modal verb, imperative

In the main clause, we can also use may, might, can, must, should instead of will.

  • If he doesn’t train harder, he may/might lose the championship.
  • If your room is tidy, you can leave.
  • If you want to lose weight, you must/should eat less sugary things.

We can also use an imperative instead of will.

  • If you arrive after midnight, ring me on my mobile.


When, as soon as, before, after, until

When we use a verb after when, as soon as, before, after or until to talk about the future, we have to use this verb in the present tense (NOT future). We use the future in the other part of the sentence.

  • I’ll retire when I will be 70. INCORRECT 
  • I’ll retire when I‘m 70. CORRECT
  • I won’t call you until I will arrive. INCORRECT
  • I won’t call you until I arrive. CORRECT

Similar to the first conditional

Future time clauses are similar to the first conditional. There’s a main clause and a when/after/etc. clause. We use the verbs in these clauses like in the first conditional.

We use a comma when the when/after/etc. clause is at the beginning of the sentence. But we don’t use a comma if the when/after/etc. clause is at the end of the sentence.

  • I’ll retire when I’m 70. 
  • When I’m 70, I’ll retire. 

We use the present in the when/after/etc. clause, and we use the future in the main clause.

  • Before you go to sleep, Daddy will tell you a story. 


In the main clause, we can also use may, might, can, must, should or an imperative instead of will.

  • As soon as you finish, you can leave. 
  • After you arrive, call me.


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