内容正文:
Lesson10时态:现在完成时
一、定义:1. 表示过去发生或已经完成的动作对现在造成影响或结果。
2. 表示从过去开始,一直持续到现在的动作或状态。
二、构成:
(1) 肯定式:主语 + has/have + 过去分词 + 其他。
eg: I have cleaned the room.
(我已经打扫过房间了。)
(2) 否定式:主语 + has/have + not(hasn’t/haven’t) + 过去分词+其他。
eg: I haven’t cleaned the room.
(我还没有打扫过房间了。)
(3) 疑问句:Have/Has + 主语 + 过去分词 + 其他。
eg: Have you cleaned the room?
(你打扫过房间了吗?)
(4) 简略答语:Yes, 主语 + have/has./ No, 主语 + haven’t /hasn’t.
eg: Yes, I have. (是的,已经打扫过了。) / No, I haven’t. (不,还没有打扫过。)
3、 过去分词
1. 规则动词:规则动词的过去分词的构成规则与规则动词的过去式的构成规则相同。四点变化规则:
(1).一般动词,在词尾直接加“ ed ”。
work—worked—worked ,visit—visited—visited
(2).以“ e ”结尾的动词,只在词尾加“ d ”。
live—lived—lived ,
(3)、以“辅音字母 + y ”结尾的动词,将y 变为i,再加“ ed ”。
study—studied—studied ,cry—cried—cried
(4)、重读闭音节结尾,末尾只有一个辅音字母,先双写该辅音字母,再加“ ed ”。
stop—stopped—stopped , drop—dropped—dropped
2. 不规则动词:
cost—cost—cost shut—shut —shut spread —spread—spread
read —read —read (read原形发音为/ri:d/,过去式和过去分词发音为/red/)
come —came —come burn— burnt —burnt catch —caught —caught dig —dug —dug
feel —felt —felt fight—fought — fought make—made — made break —broke —broken
choose—chose—chosen write —wrote —written
四、现在完成时的用法及标志
1. 表示过去发生的动作对现在造成的影响或结果。(表示到现在为止动作或状态已经、刚刚或还没有发生。)
eg: I have already finished my homework.
--- Have you had lunch yet?
--- Yes, I have. I've just had it.
注意:already用于肯定句。 He has already known it.
yet用于否定句或疑问句。 Have you done the work yet?
常见的标志语:
already,yet, never ever ,just ,before, so far, by now,till now,up to now,recently,lately,in the past/last few(或其它数字)years,over the years
2. 动作或状态从过去开始,一直持续到现在。(通常与表示段时间的时间状语连用)
常见的标志语:for, since .
eg: He has lived in Chengdu for 5 years.
eg: I have worked in the school since 1989.
注意:(1) for +段时间。如:for two weeks.(长达两个星期)
(2) since +时间点(since two days ago/ since last year / since 9:00/ since Friday .