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 since September since 1990 since 7 o’clock
b. since+一段时间+ago； 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，且居中出现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：
第 1 页
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
5. begin--be(on) begin began begun
6. join--be a member of join joined joined
be in join joined joined
7.become--be become became become 8.Open\\close--be open open opened opened
9.finish--be over finish finished finished
10.put on--wear put put put
11.catch a cold--have a cold catch caught caught 12.go to--be in go went gone
13.get to know--know get got got
14.Arrive in\\at--be in arrive arrived arrived
第 2 页
have had
be been
be a member of been a member of be in been in
be been
be open been open
be over been over
wear worn
have had
be in been in
know known
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 achool_____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 in3, 而be的过去分词为been因此我们填写的内容为 has been in
第 3 页