现在完成时难点瞬间动词转换成延续性动词.

现在完成时之瞬间动词转变成延续性动词

一、for\since:

1)for+一段时间，常常可以发现for+数字，for three months for a long time for many years

2)Since+时间点，常常可以发现

a.since+月份，年份，表示时间的几点

b.since September since 1990 since 7 o’clock

c.since+一段时间+ago；

d.since two years ago since ten months ago

c. since+ last+....

since last month since last year

二、现在完成时的结构式has\have done 请注意第三人称：she\he\人名...+has

三、当句子为肯定句，且句子中出现for\since的时候，句中的时态要用现在完成时，且句中的动词要用延续性动词。

当句子为否定句时，句中的动词可以为瞬间动词，表示某个动作不发生的状态已经持续了......

四、在有for\since的现在完成时的从句中，如何将瞬间动词转换成延续性动词

以borrow——keep为例子

They borrowed it last week. They have kept it since last week. 分析：

1）我们已经知道现在完成时的标志就是has\have done，因此第一步就是看主

语，主语时They，我们选择have done。

2）因为borrow——keep.而keep——过去分词：kept，因此，have borrowed 就需要改成have kept.

3）Since后面只能接时间点，而last week就是一个时间点，因此，since后面直接填写last week。

五、常考的瞬间动词：

原形过去式过去分词动词原形动词过去分词

1.die--be dead die died died be dead been dead

2.borrow--keep borrow borrowed borrowed keep kept

3.leave--be away from leave left left be away from been away from

4.buy--have buy bought bought have had

5.begin--be(on) begin began begun be been

6.join--be a member of join joined joined be a member of been a member of

be in join joined joined be in

been in

7.become--be become became become be been

8.Open\close--be open open opened opened be open been open

9.finish--be over finish finished finished be over been over

10.put on--wear put put put wear worn

11.catch a cold--have a cold catch caught caught have had

12.go to--be in go went gone be in been in

13.get to know--know get got got know known

14.Arrive in\at--be in arrive arrived arrived be in been in

15.Move\come\get to--be in

16.go out--be out go went gone be been

Move\come\get to--be in be in been in

举例

Mr. Smith came to this school in September.

Mr. Smith has been at this school since September.

分析：

1, come--came--come

2, 本来应该是填写has come to，但是come to要转换成be in 3, 而be的过去分词为been因此我们填写的内容为has been in 4，因为句子中已经有了at，所以我们只需要填写has been