'didn't used to do sth' 为什么前面用了过去式后面还用used?

be used to do sth.否定形式是什么?也就是说,didn't used to do 还是didn't use to do 'didn't used to do sth' 为什么前面用了过去式后面还用used? used not to do didn't use to do sth 区别 used to do 的否定式didn't use to do 中的use怎么读? use to do的一种否定 形式是：didn't used to和didn't use to ? 是didn't used to 还是 didn't use to used not do和didn't used to do有什么区别前者是做情态动词吗? The foreigners __there,but they __the food there at first.A used to live ,didn't be used to B are used to living,didn't used to C used to live,weren't used to D used to living,usedn't to 选C 为什么选C be used to do 怎么用?后一个 空 不理 英语：“used to do sth”的过去式是“didn't use to do sth”吗?不好意思啊，是否定式。 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 英语中的used to do 的否定式还有疑问句怎么变换 是“didn‘t use to do”“did you used to”吗 since的问题5.-Do you smoke?-No,I don't.But I used to.It's two years since I ______ .A.smoked B.didn't smoke C.have smoked D.began to smoke为何不是完成时? He ________Beijing opera,but he‘s very fond of it nowA don't used to B didn't use like C didn’t use to like D used not like 求翻译和解释答案 否定形式是否有didn't used to You used to be short ,didn’t you? used to do改为否定句Jack used to live in a small village with his grandpa.改为否定句印象里不是应该在used和to之间加not吗?为什么答案是didn't use to i didn't mean to do 急 Do you know John’s new address?Here’s his mail and I want to send it to him.A、Sorry,I don’t think I will do this.B、Well,we used to be roommates.C、Well,we will never meet again.D、Sorry,we didn’t get along before he moved