Definition:

Conditional sentences have two parts, one of them contains condition whereas the other contains its result.

The part of a conditional sentence which contains condition in it is called Dependent Clause or If Clause and the other part which contains its consequence is called Independent Clause or Main Clause.

Example:

                          If she works hard, she will pass.

            ↓             ↓

       Dependent clause                         Independent clause

Types of Conditional Sentences:

There are four types of conditional sentences. These are as mentioned below.

1.      Zero Conditional (General truths + Scientific facts)

Zero conditionals express general truths and scientific facts.  These sentences have present tense in both dependent and independent clauses.

  Formation:

Example:

1. If it rains, the floor gets
2. When the sun rises, the darkness disappears.

In these examples, we observe that present tense is used in both clauses. This combination renders them zero conditional sentences.

2.     First Conditional (Open Condition)

These conditionals have open condition in them. Anyone who fulfills the condition described in If Clause may enjoy the reward offered in the Main clause.

Formation:

Example:

1. If he comes, I shall give him a surprise.
2. If you work hard, you will pass.
3. Students will learn if they ask
4. He will grant us leave if we request
5. I shall offer prayer when the clock strikes

3.     Second Conditional (Imaginary Condition)

       These sentences express a condition which cannot be fulfilled.

Formation:

Example:

1. If I were a bird, I would sing sweet songs.
2. You could withdraw Pakistan from challenges if you were
3. If I had two Billion rupees, I should give them to the poor.
4. If I were a fish, I would swim the whole day.
5. If you were an airplane, you would fly distant countries.

4. Third Conditional (Unfulfilled Past Condition)

These sentences express past unfulfilled condition.

Formation:

Example:

1. If he had worked hard, he would have passed.
2. If you had been my class fellow, we would have spent a good time.
3. If he had not played wrong shot, we could have won the match.