First conditional

First conditional sentences are used to talk about real and possible situations. Here we use a simple present tense in the if-clause and will, can or may in the result clause.

If you eat too much, you will get fat.

If she works hard, she will pass the test.

If you start early, you will reach there before noon.

If I get my visa, I may go to Australia.

If I don’t get this job, I will start a business.

Second conditional

The second conditional is used to talk about situations that are less probable, imaginary or impossible.

Here we use a simple past tense in the if-clause and would / could / might + infinitive in the result clause.

If she worked hard, she would pass. (Her chances of working hard are pretty low. That is why we use the past tense in this case.)

If I won this race, my parents would be proud of me. (My chances of winning the race are pretty low.)

If he behaved more responsibly, he wouldn’t land in trouble. (He is unlikely to behave responsibly.)

Third conditional

The third conditional sentences are used to talk about past situations that did not happen. Here we use a past perfect tense in the if-clause and would have + past participle in the main clause.

If he had behaved more responsibly, he wouldn’t have landed in trouble.

If she had worked harder, she would have passed.