時態(tài)

　　國考中的考試重點是完成時態(tài)，現(xiàn)在我們詳細(xì)講完成時態(tài)的用法。

　　只有延續(xù)性動詞可以和時間段連用,瞬間動詞要改為相應(yīng)的持續(xù)性的表示狀態(tài)的短語。

　　die-be dead

　　leave/go-be away

　　buy/borrow-keep/have

　　start/begin-be on

　　注意重要句型：

　　It is (has been)…since…這一結(jié)構(gòu)也常用于現(xiàn)在完成時。

　　It has been (也可用is) a long time since they last met each other.

　　“This/It/That be the first (second) time that…”句型中，從句常用完成時態(tài)。

　　例如：Is this the first time that you have visited Hong Kong?

　　This will be the second time that I have broken a cup this week.

　　That was the third time he had been interrupted that afternoon.

　　**現(xiàn)在完成進(jìn)行時表示一種不間斷的動作，因此在提到做某事的次數(shù)或所做事情的種類時，不能用該時態(tài)，而只能用現(xiàn)在完成時.

　　I have knocked at the door five times, but I’m afraid nobody is in.

　　The pop singer has sung three songs.

　　關(guān)于過去完成時

　　1. 由had +過去分詞構(gòu)成，表示在過去某一時刻以前已經(jīng)完成的動作，常與由by, before，until等介詞或連詞引起的表示到過去某一時間為止的時間狀語連用。

　　The girl had learned a lot of English words before she went to school.

　　2.用在表示與過去情況相反的虛擬句的從句中。

　　If he had studied hard last term, he would have passed the examination.

　　I wish I had gone to the party last night.