Conditional sentences describe something that might happen in the future or might have happened in the past.
The Zero Conditional
The zero conditional for general facts and general habits.
(If + present simple / present simple)
- If we push the button, it starts the machine.
- He gets angry if he gets stressed.
The zero conditional can also be formed using “when”.
- When you heat ice, it melts.
The First Conditional
The first conditional for things which might possibly happen or are likely to happen in the future.
(If + present simple / will + infinitive)
- If it rains, I’ll take an umbrella.
- We will lose money if there is a downturn in the economy.
The Second Conditional
The second conditional for things which are not true in the present or are unlikely in the future.
(If + simple past* / would + infinitive)
*Instead of I / you / he / she /it was, it is possible to say I / you / he / she /it were.
- If I was (were) you, I would ask for a pay rise.
- If he spoke French, we would send him to France.
- We would need to employ more workers if we won the contract.
The Third Conditional
The third conditional is used for things that didn’t happen in the past and the possible consequences if that thing had taken place.
(If + past perfect / would + have + past participle)
- If I had studied business, I would have earned more money.
- She would have been promoted if she hadn’t had an argument with the boss.
Mixed conditionals combine different conditional forms to express the desired meaning. This is normally to express something that didn’t happen in the past and the possible consequence in the present if that thing had taken place.
(If + past perfect / would + infinitive)
- If I had studied business, I would earn more money today.
- I would be head of department if the company hadn’t hired someone from outside.