seem to be doing sth ,seem to do ,seem to have done sth这三者有什么区别,

Question

seem to be doing sth ,seem to do ,seem to have done sth
这三者有什么区别,

Answer 1

seem to be doing sth表示不定式的动作和主句中seem是同一个时态,比如,He seems to be doing his homework.他好像正在做作业；
seem to do 表示不定式的动作发生在主句动词seem之后,比如It seems to rain.好像要下雨了.rain的动作,是发生在seem之后的；
seem to have done sth表示不定式的动作发生在主句动词seem之前,比如 she seems to have finished her homework.她好像做完了她的家庭作业.finish的动作发生在seem之前