最新整理（四）！高考英语24语法，带你攻克高中所有语法难点！(29)

⒒ so far（到目前为止）
如：So far she has learned 5 English songs.
⒓ up to now（到目前为止）
⒔ this morning/month/year（今天早上/这个月/今年）
㈣ 现在完成时的用法
⒈ 现在完成时表示过去发生的动作，并对现在有影响。常与already(已经），yet(已经），just（刚刚），ever(曾经）等词连用。
⒉ Already,yet的用法
already：常用于肯定句中.
yet：常用于否定句，疑问句尾。
如：Someone has broken the window.（窗户现在是坏的。）
I have already lost the key.（我现在没有钥匙）
I have just cleaned my hands.(手是干净的）
⒊ 现在完成时表示从过去一直持续到现在的动作或状态，常与for，since引导的时间短语或从句连用.
① since，for的用法：
⑴ since（自……以来）
a. since 时间点
如：He has stayed here since 5 o"clock.
b. since 时间段 ago
如：He has stayed here since 5 hours ago.
c. since 从句
⑵ for（长达）
a. for 时间段
如：He has kept the book for 2 weeks.
She has learned English for 5 years.
He has lived in Beijing since he was born.
Have you stayed here since 3 o"clock?
⒋ have/has been to；have/has gone to；have/has been in
have /has beento 曾经去过某地，人已经回来了
have /has gone to 去了某地，人还没回来
have /has been in去了某地并一直待在那