内容正文:
第11练 含有for和since的现在完成时
since和for是现在完成时当中常见的标志词。since“自从……”,for“持续了……”。since用来说明动作的开始时间,for用来说明动作延续的时间长度
考点1 since和for是现在完成时的重要标志
考点2 since和for的用法
(1)since的用法
since+过去的时间点。如:年、月、日、几点等
☞since 1990 自从1990年起
☞since 5 o’clock 自从五点起
since+ 时间段+ ago
☞since 3 months ago 自从三个月以前
since+ 一般过去时的从句
☞since you left home 自从你离开家以后
(2)since的一个固定句式“It is+时间段+since+一般过去时的从句”。
It is five years since I came here. 我来这儿5年了。
(3)for的用法:for+时间段
(4)在现在完成时当中,若对since和for引导的时间状语进行提问,都可以用how long来提问。
(5)since和for的句式转换:
since+时间段+ago=for+时间段
They haven't changed since twenty years ago.
=They haven't changed for twenty years.
他们已经二十年没有改变了。
考点3 延续性动词、短暂性动词与since, for
延续性动词表示能够延续的动作。短暂性动词表示不能延续的动作,这种动作发生后立即结束。
(1) 若现在完成时的句子中含表示时间段的时间状语(如含since/for引导的时间状语),则谓语只能使用延续性动词。
(2) 短暂性动词可以转化为延续性动词
①直接换成延续性动词
buy买→have有 borrow借→keep保留 put on穿上→wear穿着come/go/become来/去/变成→be在/是
②转换成be+名词
join the army参军→be a soldier当兵 join the Party 入党→be a Party member成为一名党员
go to school去上学→be a student成为一名学生
③转换成be+形容词/副词
die死亡→be dead死了 finish结束→be over结束
begin开始→be on 在上映/已开始 leave离开→be away远离的
fall asleep入睡→be asleep睡着的 close关闭→be closed关着的
④转换成be+介词短语
go to school去上学→be in school在上学
join the army参军→be in the army在军队中
一、单项选择
1.—How long ________ here?
—For only five minutes. My sister ________ here with me.
A.have you been; walked B.are you; has walked C.are you; walked D.have you gone; has walked
2.How many Chinese astronauts ________ into space since 2003?
A.were sent B.sent C.have been sent D.have sent
3.John ________ the club for three years. It means he ________ the club three years ago.
A.has joined; has joined B.has been a member of; joined
C.has taken part in; joined D.has become a member of; has joined
4.— _________ have you studied in this middle school?
— Since two years _________.
A.How long; before B.How much time; before
C.How soon; ago D.How long; ago
5.It _________ five years since we last _________ each other.
A.is; has seen B.is; saw C.was; saw D.has been; have seen
6.