时态

　　国考中的考试重点是完成时态，现在我们详细讲完成时态的用法。

　　只有延续性动词可以和时间段连用,瞬间动词要改为相应的持续性的表示状态的短语。

　　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…这一结构也常用于现在完成时。

　　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，从句常用完成时态。

　　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.

　　**现在完成进行时表示一种不间断的动作，因此在提到做某事的次数或所做事情的种类时，不能用该时态，而只能用现在完成时.

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

　　The pop singer has sung three songs.

　　关于过去完成时

　　1. 由had +过去分词构成，表示在过去某一时刻以前已经完成的动作，常与由by, before，until等介词或连词引起的表示到过去某一时间为止的时间状语连用。

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

　　2.用在表示与过去情况相反的虚拟句的从句中。

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

　　I wish I had gone to the party last night.