短暂性动词,延续性动词和现在完成时
延续性动词是指动作发生后还可以延续一段时间或者相当长的一段时间。如：live, work, study, learn, sleep 等，延续性动词可以和表示一段的时间状语连用。
传宗接代英文短暂性动词是指动作一旦发生就立即结束。它不能和一段时间连用。这类动词有：go, come, arrive, leave, begin, start, join, marry 等；
★在否定句中，短暂性动词可以和表示一段时间的状语连用。
We haven’t heard from Jane for a long time.
★短暂性动词的肯定式不能与表示一段时间的for 或since 或how long 等状语连用。★值得注意的是，表示一段时间的状语除了“for+一段时间”外，还有since+n./从句（时间点），since+时间段+ago ，疑问词how long ，in the past+时间段，all the+时间段，from…to （时间点）以及till/until+n./句子等等。例如：
.I have received his letter for three days （×） I have received his letter.（√） How long d
id she leave .（×） How long has she been away (√) ★★★如果短暂性动词与表示一段时间的时间状语连用，必须将短暂性动词改为延续性动词。现归纳总结一下由非延续性动词到延续性动词的转换：
arrive→be here ★除了用上面的转化形式之外，还可以用其他的表达形式：
A. It is 或者 It has been+时间+since……（动词用过去式），
B.主语+谓语（过去时）+时间+ago 。 例如：
It’s fi ve days since I received his letter.
His father died three years ago.
arrive→be here
begin(start)→be on
die →be dead
come back→be back
leave →be away (from)高中辅导班
fall ill(asleep)→be
ill( asleep) get up→be up go out →be out finish →be over put on →wear 或be on open →be open clo →be clod jo in →be in / be a member of go to school→be a student borrow→keep buy/get→have catch(a cold)→ have(a cold) get to know →know begin to study→study come to work→work move to → live in finish/end → be over come to → be in sit down → be at ed
看一个句子可以用以下几种说法：他离开上海已经3天了。
He left Shanghai three days ago.
He has been away from Shanghai for three days/since three days ago
It is/has been three days since he left Shanghai.
Three days has pasd since he left Shanghai.
几点注意事项:
（1）have been(to)与have gone( to)的区别：
have been(to)表示“去过某地（现在已经回来了）”，可用于各人称；
have gone(to)表示“去某地了（说话时某人不在当地）”，可能在去的路上，可能已在某地，也可能在回来的路上，总之，人不在这里。常用第三人称作主语。
前者可与once,never, veral times等连用，后者则不能。
如：They have been to Beijing twice.他们去过北京两次。
He has gone to Beijing他去北京了。
tiffany啥意思
注意比较 has gone to, has been to, has been in的意义：
He has gone to Amercia. （他到美国去了。他不在这里）
He has been to Amercia. （他去过美国。现已回来）
He has been in Shanghai. （他在上海呆过。现在不在上海）
He has been in shanghai for years. （他在上海多年。现在还在上海）
惊喜用英语怎么写
（2）终止性动词现在完成时的否定式，已变成一种可以延续的状态，因此可以和表示一段时间的状语连用。
赶快的英文如：I haven 't left here since 1997.自从1997年以来，我一直没有离开过这儿。
★另外，动词的延续性与非延续性还体现在这两种句型中：
鞭笞延续性动词的肯定式+till/until
短暂性动词的否定式+till/ until
请看例句：We waited until he came.
I didn’t go to bed until my father came back home last night.
短暂性动词，延续性动词和现在完成时练习
I. 句型转换：
1. Mr. Li began to teach English in this school in 1999.（同义句）
Mr. Li ______ _______English in this school since 1999.
2. The factory opened ten years ago.（同义句
The factory _______ _____ ______ for ten years.
3. John left Beijing three years ago. （同义句）
Three years _____ _____ ______ John _____ Beijing.
John_____ ______ ______ ______ Beijing _____ three years.
4. His company opened in 2003. （同义句
His company _____ _____ _____ since 2003.
5. My father bought the car half a year ago. （同义句
My father ______ ______ the car ____ half a year.
6. We got to know each other for about 15 years.（同义句
We _____ _____ each other _____ about 15 years.
stake7. The film began ten minutes ago. （同义句
The film _____ _____ ____ for ten minutes.
8. I borrowed this book two weeks ago. （同义句
I _____ _____ this book for two weeks.
四级词组
thailand是什么意思9. My father came back the day before yesterday.
My father has ______ ______ for two days.
uncle bought the new car two months ago.
bec官网My uncle has______ the new car ______two months ago.
II. 用have been和have gone填空。
1. Mother isn’t here. She ______ to the barber’s.
