Conditional Sentences

Conditional sentences are statements discussing known factors or hypothetical situations and their consequences. Complete conditional sentences contain a conditional clause (the if-clause) and the consequence.

It is important to use the correct structure for each of the different conditional sentences because they express varying meanings.

Use a comma after the “if-clause” when the “if-clause” precedes (comes before) the main clause.

If the main clause precedes the “if-clause”, no comma should be used in the sentence.

 

There are four types of conditional sentences.

1. Zero conditional sentences.

2. First conditional sentences.

3. Second conditional sentences.

4. Third conditional sentences.

 

Zero conditional sentences:

Zero conditional sentences express general truths – situations in which one thing always causes another.

When using the zero conditional, the correct tense to use in both clauses is the simple present tense. (A common mistake is to use the simple future tense.)

The words “if” and “when” can be used interchangeably in zero conditional sentences because the outcome will always be the same.

 

 

 

Sentence structure:

If + simple present tense, + simple present tense.

 

Examples:

1. If people eat too much, they get fat.

2. If babies are hungry, they cry.

3. If water reaches 100 degrees, it always boils.

4. Snakes bite if they are scared.

5. People die if they don’t eat.

 

First conditional sentences:

The first conditional sentences are used to express situations in which the outcome is likely (but not guaranteed) to happen in the future.

First conditional sentences are used to talk about things which might happen in the future.

In first conditional sentences, we use the simple present tense in the “if-clause” and the simple future tense in the main clause.

 

Sentence structure:

If + simple present tense, + simple future tense.

 

Examples:

1. If you take rest, you will feel better.

2. If I have enough money, I will buy new clothes.

3. If it rains, I will not go to the party.

4. If you come early, we will go for a walk.

 

A common mistake is to use the simple future tense in the “if-clause”.

 

 

Second conditional sentences:

The second conditional sentences are used for expressing outcomes that are completely unrealistic or will not likely happen in the future.

Second conditional sentences are used to talk about things in the future which are probably not true or, to talk about something in the present which is impossible.

The correct way to structure second conditional sentences is to use the simple past tense in the “if-clause” and an auxiliary modal verb (e.g. would, could, should, might) in the main clause.

 

Sentence structure:

If + simple past, + sub + would + v1 + obj.

 

Examples:

1. If I won the lottery, I would buy a big house.

2. If I were you, I would work hard.

3. If I owned a zoo, I might let people interact with the animals more.

 

A common mistake is to use the simple present tense in the “if-clause”.

 

 

 

 

Third conditional sentences:

The third conditional sentences are used to explain that present circumstances would be different if something different had happened in the past.

The third conditional sentences are used to talk about unreal situations in the past or, to talk about things which did not happen in the past.

The third conditional sentences are used to talk about impossible conditions because they happened in the past and we can not change them.

These sentences also express regret.

 

 

Sentence structure:

If + past perfect tense, + sub + would/could/might + have + past participle (v3) + obj.

 

Examples:

1. If you had driven more carefully, you would not have had an accident.

2. If she had saved her money, she could have bought a computer.

3. If it had snowed, we could have gone skiing.

4. If we had played better, we could have won the game.

5. If they had spoken a bit slower, I would have understood them.

 

A common mistake is to use would have + past participle in the “if-clause”.