什么时候用don't have one,什么时候用don't have a

什么时候用don't have one,什么时候用don't have a 什么时候用in on at to of for with;什么时候用don‘t have like,什么时候用doesn have什么时候否定为haven't什么时候为don't have? 英语语法说明什么时候用doesn't , 什么时候用don't. don't 和can't 有什么区别什么时候用can't,什么时候用don'tt 什么时候用not否定什么时候用don't否定 i don't have a Don't have a cow! Don't have a cow don't have a seat为什么要用don't而不用doesn't A.have;does't have B.have;don't have C.don't have I don't have a computer.Does she got one?