used to 过去常常.是过去式,可有一句话he didn't used to.存在吗/
used to 过去常常.是过去式,可有一句话he didn't used to.存在吗/
used to do sth 是过去常常做某事的意思、 do 要不要用过去式?例 he used to get up g
英语:“used to do sth”的过去式是“didn't use to do sth”吗?
是didn't used to 还是 didn't use to
used to do 过去常常做
used to 当过去常常解释时的被动语态是用be used to 还是用used to be
has been used to detect gold,这是什么时态?句中的used to 是表示过去常常做某事吗?
'didn't used to do sth' 为什么前面用了过去式后面还用used?
.He used to be a heavy smoker,_______?A.used he B.didn’t he
Tom didn't used to be quiet,he used to be o____.
used to do是过去常常,那use to do是不是现在常常呢
否定形式是否有didn't used to