There are several structures in English that are called conditionals.
"Condition" means "situation or circumstance". If a particular condition is true, then a particular result happens.
People sometimes call conditionals "IF" structures or sentences, because there is usually (but not always) the word "if" in a conditional sentence.
We are talking about the future. We are thinking about a particular condition or situation in the future, and the result of this condition. There is a real possibility that this condition will happen.
IF
|
condition
|
result
|
present simple
|
WILL + base verb
| |
If
|
it rains
|
I will stay at home.
|
More examples:
| IF | condition | result |
| present simple | WILL + base verb | |
| If | I see Mary | I will tell her. |
| If | Tara is free tomorrow | he will invite her. |
| If | they do not pass their exam | their teacher will be sad. |
| If | it rains tomorrow | will you stay at home? |
| If | it rains tomorrow | what will you do? |
| result | IF | condition |
| WILL + base verb | present simple | |
| I will tell Mary | if | I see her. |
| He will invite Tara | if | she is free tomorrow. |
| Their teacher will be sad | if | they do not pass their exam. |
| Will you stay at home | if | it rains tomorrow? |
| What will you do | if | it rains tomorrow? |
Sometimes, we use shall, can, or may instead of will, for example: If you are good today, you can watch TV tonight.
The second conditional is like the first conditional. We are still thinking about the future. We are thinking about a particular condition in the future, and the result of this condition. But there is not a real possibility that this condition will happen.
IF
|
condition
|
result
|
past simple
|
WOULD + base verb
| |
If
|
I won the lottery
|
I would buy a car.
|
More examples:
| IF | condition | result |
| past simple | WOULD + base verb | |
| If | I married Mary | I would be happy. |
| If | Ram became rich | she would marry him. |
| If | it snowed next July | would you be surprised? |
| If | it snowed next July | what would you do? |
| result | IF | condition |
| WOULD + base verb | past simple | |
| I would be happy | if | I married Mary. |
| She would marry Ram | if | he became rich. |
| Would you be surprised | if | it snowed next July? |
| What would you do | if | it snowed next July? |
Sometimes, we use should have, could have, might have instead of would have, for example: If you had bought a lottery ticket, you might have won.
With the third conditional we talk about the past. We talk about a condition in the past that did not happen. That is why there is no possibility for this condition. The third conditional is also like a dream, but with no possibility of the dream coming true.
| IF | condition | result |
| past perfect | WOULD HAVE + past participle | |
| If | I had seen Mary | I would have told her. |
| If | Tara had been free yesterday | I would have invited her. |
| If | they had not passed their exam | their teacher would have been sad. |
| If | it had rained yesterday | would you have stayed at home? |
| If | it had rained yesterday | what would you have done? |
| result | IF | condition |
| WOULD HAVE + past participle | past perfect | |
| I would have told Mary | if | I had seen her. |
| I would have invited Tara | if | she had been free yesterday. |
| Their teacher would have been sad | if | they had not passed their exam. |
| Would you have stayed at home | if | it had rained yesterday? |
| What would you have done | if | it had rained yesterday? |
Sometimes, we use should have, could have, might have instead of would have, for example: If you had bought a lottery ticket, you might have won.
ZERO CONDITIONAL
Take some ice. Put it in a saucepan. Heat the saucepan. What happens? The ice melts (it becomes water). You would be surprised if it did not.
| IF | condition | result |
| present simple | present simple | |
| If | you heat ice | it melts. |
Some examples:
| IF | condition | result |
| present simple | present simple | |
| If | I miss the 8 o'clock bus | I am late for work. |
| If | I am late for work | my boss gets angry. |
| If | people don't eat | they get hungry. |
| If | you heat ice | does it melt? |
