If clauses

The if clauses in English are the conditional clauses used in various situations and are always accompanied by the term If (if). If clauses: in English Grammar with examples

They are used to talk about future plans, probable or unlikely situations to happen, or even choices that have been made in the past.

Classification

The clauses if they are formed by two sentences: a clause if (conditional sentence) and the main clause (main clause). That is, a subordinate and a main clause.

They are classified in four ways:

Zero Conditional

It indicates true facts that occur frequently, and it is also used to give orders. Its formation is:

if + simple present + simple present

Examples :

If I study a lot, I get tired.  If clauses: in English Grammar with examples
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First Conditional

Indicates possibilities or probable future actions. Its structure is:

If + simple present + simple future + infinitive

Examples :

If you buy one of these books now, I can get a good price for you.
If I go to London, I can buy an English guidebook. If clauses

Second Conditional

Indicates situations that are unlikely or that may even be unreal in the future. Its structure is:

If + simple past + would, could, might, should + infinitive (without to)

Examples :

If I had lots of money, I could buy a big house.
If I lived in Brazil, I would be happy.

Third Conditional

It indicates something that has not occurred in the past and, therefore, often expresses regret. Its formation is:

if + past perfect + would have, could have, might have + past participle

Examples :

If we had saved some money, we would have bought a new car.
If she had come on Saturday, I would have seen her.

If clauses: in English Grammar with examples