大學英語四級語法精要 大學英語四級語法精要

大學英語四級語法精要

Ⅰ動詞(時態(tài),語態(tài),用法,省略,一致性等)

1.   時態(tài)

1)現(xiàn)在完成進行時態(tài) (have/has been + -ing 分詞構成): 動作或狀態(tài)從過去某時開始,繼續(xù)到現(xiàn)在,可能繼續(xù)下去,也可能剛剛結束.

I’ve been writing letters for an hour.

I’ve been sitting in the garden.

2)過去完成進行時(由had been + ing分詞構成): 過去某個時刻以前一直在進行的動作

I’d been working for some time when he called.

We had been waiting for her for two hours by the time she came.