现在完成时Since和for的用法
Since 和for 的用法
表示过去已经开始持续到现在的动作或状态常用的时间状语有：for, since, how long, so far, these days等。

Since+过去点的时间，for+一段时间(数词+量词)，此划线部分用how long提问。

一、since短语或从句表示过去的动作延续至今，since之后的时间为一点。

如：
Mr. Smith has worked here since 1984. 1984年以来，史密斯先生一直在这工作。

He’s learned about 5,000 English words since he went to college. 他上大学以来大约学了五千个英语单词。

二、for短语表示动作延续多长时间，for的宾语为时间段。

如：
We have known each other for twenty years. 我们认识有二十年了。

I haven’t seen her for a long time. 我好久没有见到她了。

练习：用since和for填空
1) ______ two years 2) _______ two years ago 3) _______ last month
4) ______ 1999 5) _______ yesterday 6) _______ 4 o’clock
7) ______ 4 hours 8) _______ an hour ago 9) _______ we were children
10) _____ lunch time 11) ______ she left here
1. He has lived in Nanjing ________ the year before last.
2. I’ve known him __________ we were children.
3. Our teacher has studied Japanese _________ three years.
4. She has been away from the city ___________ about ten years.
5. It’s about ten years __________she left the city.
2.短暂性转换延续性
①arrive at/in sw. get to/reach sw. come/go/move to sw.
→ be in sw./at school/at home/on the farm/be here/be there
1) He got to Beijing five minutes ago.
He ________ _________ _________ Beijing for _________ _________.
2) I moved to the USA last year.
I ________ ________ __________ the USA since __________ __________.
3) I went home yesterday.
I _______ ________ _________ home for _________ __________.
4) They came here last week.
They _________ _________ here since _________ __________.
②come/go back, return → be back come/go out → be out
1) He came out two years ago.
He _________ __________ _________ for __________ __________.
2) We return to Fuzhou yesterday.
We ________ ________ _________ to Fuzhou since __________.
③become → be
1) I became a teacher in 2000.
I ________ __________ a teacher for _________ _________.
2) The river became dirty last year.
The river _________ _________ dirty for _________ __________.
④close → be closed open → be open
1) The shop closed two hours ago.。