介绍:
M: Where have you been, Kate?
F: I've been at the garage for the last two hours.
M: What happened? Did you have an accident?
F: No, nothing happened. But we haven't had the car checked since February. It's needed an oil change for a long time.
M: I know. Have you gotten the car back?
F: No. They've worked on it since four thirty, but they haven't finished it yet.
M: Well, when can we get it back?
F: I'll pick it up on Friday.
M: That's good. Then, we'll have it for the weekend.
since 与 for 这个两个字常常跟现在完成式句子一起用. since 表示 "自从一个特定的时间开始", for 表示 "时间持续了多久"后面加段时间.
Henry and Kate have been married since 1962.
They have been married for a long time.
Henry and Kate have lived in Seattle since 1965.
They have lived in Seattle for a long time.
M: Henry has worked as a fireman since 1970.
F: He has worked as a fireman for many years.
so far当so far表示“到目前为止”时，它指的是从过去某时持续到现在的一段时间，因此通常与现在完成时连用。So far 500 people have died in the earthquake. 到现在为止，已有500人在地震中丧生。
其他要用完成时态的标志性短语：
up to now
It’s the first（序数词） time that…
over the years
in the past five years
over the years
等等
ever和never表示到现在为止动作或状态曾经或从来没有发生过
英语中的动词从词义上可以分为延续性和非延续性两种。在现在完成时态中一定要注意动词这一特性，应将这类非延续性动词转换为延续性动词。如：
This movie has been on for half an hour. 这部电影已经开演半个小时了。（begin-be on）
How long have you had this dictionary? 这本字典你买了多久了?（buy-have）
其他这类动词同学自行掌握
