if 引导条件状语从句脑图思维导图

My mother will take me to the park if she is free.

If my mother is free, she will take me to the park.

主句是一般将来时，从句用一般现在时。

If my brother comes back, he will take me to the park.

主句含有情态动词can/may/might/must/should等，从句用一般现在时。

If you want to be healthy, you should keep a good diet.

主句是祈使句，从句用一般现在时。

Don’t play with the knife if you don’t want to get hurt.

If you get up early, you'll get there on time. = Get up early, and you'll get there on time.

If there is no water, fish will die. = Fish will die without water.

You will be late if you don't go there by bus. = You will be late unless you go there by bus.