Can't
Has to
Had to
Can
Have to
It is used to express ability or to say that something is possible. You use it with all subject (I, you, she, he, it we, they)
It is used to express that someone doesn't have the ability or to say that something is not possible. You use it with all the subjects
It's use to talk about obligation, things that are necessary to do. Also you only use it with first and second person (I, you, we, they)
It's use to talk about obligation, things that are necessary to do. It's used for the past tense and you use it with all the subjects
It's use to talk about obligation, things that are necessary to do. Also you only use it with third person (he, she, it)
