This document discusses the four types of conditionals in English: 1) Zero conditional uses the present simple to talk about general truths. 2) First conditional uses will or other modals with the present tense to talk about possible or likely situations now or in the future. 3) Second conditional uses would or other modals with the past simple to talk about impossible or unlikely situations now or in the future. 4) Third conditional uses would have with the past perfect to talk about hypothetical situations in the past. Each conditional structure is explained with examples.

1. Zero, First, Second and Third Conditionals

2. Zero conditional
 Use – to talk about general truths
E.g. If you have a brother or sister, you are not an only
child.
Note: You are not an only child if you have a brother
or sister.
 Structure: If + present simple, present simple

3. First conditional
 Use – to talk about possible or likely situations now or in the
future
E.g. If it rains tomorrow, we’ll stay at home.
 Structure:
If + present tenses (simple, continuous and perfect) + will + b.i.

4.  It is possible to use other modals instead of will:
If you finish the test early, you can go home.
If you work hard, you should pass the exam.
If I am tired, I may/ might decide not to go to the party.

5. Second conditional
 Use – to talk about impossible or unlikely situations
now or in the future
E.g. If I found a wallet on the street, I would take it to the police
station.
If I didn’t go to the party, I’d be upset.
 Structure:
If + past simple or continuous + would + b.i.

6.  It is possible to use other modals instead of would:
I am not tired. If I went to bed now, I couldn’t sleep.
If I lived on my own, I might decide to get a dog.
In conditional sentences you can use WERE for all the subject
pronouns:
If I were rich, I would buy a big house.

7. Third conditional
 Use – to talk about hypothetical situations in the past
E.g. I decided to stay at home last night. I would have gone out if I
hadn’t been so tired.
I wasn’t hungry. If I had been hungry, I would have eaten something.
If he had been looking where he was going, he wouldn’t have walked
into the wall.
 Structure:
If + past perfect simple or continuous + would have + p. p.

8. UNLESS
We can also use UNLESS in conditional sentences. UNLESS can replace IF ... NOT:
If we don’t score another goal, we will lose. (1st Cond.)
UNLESS we score another goal, we will lose.
I couldn’t watch the match if I didn’t have a TV. (2nd Cond.)
I couldn’t watch the match UNLESS I had a TV.
If she hadn’t been such a good player, she wouldn’t have won the game. (3rd Cond.)
UNLESS she had been such a good player, she wouldn’t have won the game.

9. Source: Laser Grammar Bank Intermediate. Macmillan. P. 23 -28.