系动词分类及用法

1）状态系动词

用来表示主语状态，只有be一词，例如：

He is a teacher.他是一名教师。（is与补足语一起说明主语的身份。）

2）持续系动词

用来表示主语继续或保持一种状况或态度，主要有keep, rest, remain, stay, lie, stand, 例如：

He always kept silent at meeting.他开会时总保持沉默。

This matter rests a mystery.此事仍是一个谜。

3）表像系动词

用来表示"看起来像"这一概念，主要有seem, appear, look, 例如：

He looks tired.他看起来很累。

He seems (to be) very sad.他看起来很伤心。

4）感官系动词

感官系动词主要有feel, smell, sound, taste, 例如：

This kind of cloth feels very soft.

这种布手感很软。

This flower smells very sweet.

这朵花闻起来很香。

5）变化系动词

这些系动词表示主语变成什么样，变化系动词主要有become, grow, turn, fall, get, go, come, run.

例如：

He became mad after that.自那之后，他疯了。

She grew rich within a short time.她没多长时间就富了。

6）终止系动词

表示主语已终止动作，主要有prove, trun out, 表达"证实"，"变成"之意，例如：

The rumor proved false.这谣言证实有假。

The search proved difficult.搜查证实很难。

His plan turned out a success.他的计划终于成功了。（turn out表终止性结果）since的四种用法

1) since +过去一个时间点(如具体的年、月、日期、钟点、1980, last month, half past six)。

I have been here since 1989.

2) since +一段时间+ ago

I have been here since five months ago.

3) since +从句

Great changes have taken place since you left.

Considerable time has elapsed since we have been here.

4) It is +一段时间+ since从句

It is two years since I became a postgraduate student.

5）since和for

在现在完成时态，since后面加时间点，for后面加时间段。

延续动词与瞬间动词

1) 用于完成时的区别

延续动词表示经验、经历；瞬间动词表示行为的结果，不能与表示段的时间状语连用。

He has completed the work.他已完成了那项工作。(表结果)

I've known him since then.我从那时起就认识他了。(表经历)

2)用于till / until从句的差异

延续动词用于肯定句，表示"做……直到……" 瞬间动词用于否定句，表示"到……，才……"

He didn't come back until ten o'clock.

他到10 点才回来。

He slept until ten o'clock.

他一直睡到10点。

典型例题

1. You don't need to describe her. I ___ her several times.

A. had met

B. have met

C. met

D. meet

答案B. 首先本题后句强调对现在的影响，我知道她的模样，你不用描述。再次，several times告知为反复发生的动作，因此用现在完成时。

2.---I'm sorry to keep you waiting.

---Oh, not at all. I ___ here only a few minutes.

A. have been

B. had been

C. was

D. will be

答案A. 等待的动作由过去开始，持续到现在，应用现在完成时。[编辑本段]过去完成时1）概念：表示动作发生在过去，并在过去完成（即是常说的过去的过去）。

用一示意图表示如下：

动作发生

------|----------------|----------|---->

过去的过去过去现在

其基本构成是：had+动词过去式。

2）用法

a.在told, said, knew, heard, thought等动词后的宾语从句。

She said (that) she had never been to Paris.

b. 状语从句

在过去不同时间发生的两个动作中，发生在先，用过去完成时；发生在后，用一般过去时。

When the police arrived, the thieves had run away.

c. 表示意向的动词，如hope, wish, expect, think, intend, mean, suppose等，用过去完成时表示"原本…，未能…"

We had hoped that you would come, but you didn't.

3)过去完成时的时间状语before, by, until , when, after, once, as soon as。

He said that he had learned some English before.

By the time he was twelve, Edison had began to make a living by himself.

Tom was disappointed that most of the guests had left when he arrived at the party.

典型例题

The students ___ busily when Miss Brown went to get a book she ___ in the office.

A. had written, left B，were writing, has left C. had written, had left D. were writing, had left

答案D. "把书忘在办公室"发生在"去取书"这一过去的动作之前，因此"忘了书"这一动作发生在过去的过去，用过去完成时。句中when表示的是时间的一点，表示在"同学们正忙