辅音现在完成时的构成

2021年1月19日发(作者：人在旅途歌词)
现在完成时的构成
have∕ has + P.P.
现在完成时的用法
1完成 表示过去的动作对现在的影响。Already .yet ever just
before
He has lost his key.
2还完成 从过去一直持续到现在，是否持续下去不知道。
⑴ 一次性动作完成的
与just连用，表 示刚刚完成的动作或状态（just放在have∕has与P.P.
之间）。
I have just had lunch. He has just finished his homework.
①already 已经 肯定句中或句尾 例: I have already found my
pen. = I have found my pen already.
②yet已经 否定句和疑问句句尾 例：I have not finished the
work yet.
Have you bought a computer yet?
I have already bought the computer.
例：Have you ever seen pandas?
never从不 句中 例：I have never been to Beijing.
before以前 句尾
例：I have never been there before.
how many times多少次 three times
How many times has he been to Beijing?
havegone to去了某地
例：He has gone to Beijing (去了北京)
havebeen to去过某地
例：He has been to Beijing. (去过北京)
⑵ 表示动作发生在过去，持续到现在，有可能延续到将来，常 与
since“自从…”（后面跟一点时间）for（后面跟一段时间）连用。
I
have learned English since 2000.
He has lived there for 10 years.
例：He has bought the book for 3 years.
1)He has bought the book
2)He bought the book 3 years ago
3)It’s 3 years since he bought the book..It is three hours since he got
here . （
④ He has not bought the book for 3 years. （改为否定句）
5) He has had the book for 3 years.

①come/arrive/get to/reach → be here
例：I have come here for 3 years.（错） 改为：I have been here for 3 years.
②leave/go →be away
例：He has left for 3 hours.（错） 改为：He has been away for 3 hours.
③begin/start →be on
例：The film has begun for 3 minutes.（错）