現在完成時表示過去開始，但持續(xù)到現在的動作，或過去發(fā)生的動作，對現在留下后果或影響。常和for+一段時間，already, ever, never, just, yet, in the past few years/ over the last thirty years, so far, up to now, since 1980等狀語連用。
【例如】
Most college students have learned English for more than six years. Great changes have taken place in China in the past few years.I have never been abroad up to now.*表示短暫行為的動詞不能和延續(xù)性時間狀語連用。
【例如】
I have been back from England for over two weeks.或It has been over two weeks since he came back from England.We couldn't say: I have come back from England for over two weeks.He has been in the army since 1998. We couldn't say: He has joined the army since 1998.
【例如】
Most college students have learned English for more than six years. Great changes have taken place in China in the past few years.I have never been abroad up to now.*表示短暫行為的動詞不能和延續(xù)性時間狀語連用。
【例如】
I have been back from England for over two weeks.或It has been over two weeks since he came back from England.We couldn't say: I have come back from England for over two weeks.He has been in the army since 1998. We couldn't say: He has joined the army since 1998.