.

Conditionals are sentences in which the main-clause as well as the subordinate-clause express conditions. In each of the clauses one event follows the other or depends upon the other.

Let us look at these sentences

If it rains, I shall stay at home. (1^st Conditional)

I shall stay at home if it rains.

If it rained, I would stay at home. (2^nd Conditional)

I would stay at home if it rained.

If it had rained, I would have stayed at home. (3^rd Conditional)

I would have stayed at home if it hadrained.

We notice that in each of these sentences have two clauses – the main clause and the subordinate clause.

I will stay at home if it rains.

Main clause subordinate clause