If usage

Conditional clause:
Type 1:
If you study well, you will pass.

If you run fast, you will catch the bus.

If she calls me, I will go with her.

Type 2:
If I became a doctor, I would serve the poor.

Type 3:
If I had had study well, I would have scored good marks.

If I had known your problem, I would have given money for you.

Type 4:
If you hear water at 100 cc.
It boil.