过去式后为什么还有doing
lay是lie的过去式,为什么它还有过去式?
为什么是What were you doing,是过去式为什么要用doing,不是what were you do
will.是将来时,为什么还有过去式 would?
have been doing 为什么还有 have been dead
动词过去式后的动词为什么用原形
为什么it is time后动词可以用过去式?
为什么有的动词后的词要加-ing?如keep doing?
be able to后为什么可以加doing?
rather than 后可以加doing的情况是为什么
be absorbed in 后可以加doing sth.还有focus one's attention on ,on后
名词还有过去式?
1stop from doing sth 还是stop doing sth?2为什么must can等情态动词还有sti