used to do的否定used to do正式的否定形式是used not to do,口语中可以说didn't use to do .我想问,其他动词的否定都是在其前面加didn’t或者don't等助动词,为什么used to do的正式的否定形式要在used后面加

used to do的used的词性 used to do的否定句和疑问句 sb used to do sth.它的否定形式是什么? used to do的用法 be used to doing与used to do的区别 used to be 和 used to do 的区别 be used to 和 used to do 的区别 used to do,be used to doing和 be used to do的区别,并举例说明 翻译used to do used to doing get used to do与get used to doing的区别.used to do与used to doing used to do 造句 used to do用法 used to do用法 used to do sth. used to do sth used to do get used to do used sb to do sth?的肯定回答和否定回答是什么?例如,used lily to walk to school?Yes,she used.No,she usedn't对吗