grammar---have to

表示必需或者义务做某事

eg:

Tom has to walk to work because he do not catch the bus.

I have to take care my parents when they are old.

have to 和 must 的区别

have to 被动接受，不得不做，有勉强意味

must 自己主观意愿去做，主动性较强

eq:

You must make homework done today.