现在完成时用法注意点考点分析
现在完成时。（主语﹢have/has ﹢动词的过去分词）
现在完成时表示过去开始发生一直持续到现在的动作，强调对现在的影响。
We have lived separately since last year.
现在完成时用法注意点：
(1)两种意义的现在完成时
a.持续到现在（动词要用延续性动词）；时间状语：表示从过去延续到现在并包括现在在内的一段时间状语，如 lately, recently，up to now，so far，these days, in/over/during the last/past ten days/months/years, etc.
I haven’t had enough sleep lately.
Great changes have taken place in the past twenty years in China.
b. 对现在有影响；时间状语： already, just, ever, never ,before, not yet, etc.
Have you ever found out her telephone number?
(2) have been to VS have gone toHave been to表示曾经去过某地，现在人在说话的现场，而 have gone to 表示已经去了某地，现在人不在说话的现场。
I have been to Beijing for three times. 我曾经去过北京三次。
She has gone to Beijing. 她去北京了。
注意： ①现在完成时除可以和for、since引导的状语连用外，还可以和下面的介词短语连用：during / in /over the last(past)few years (months, weeks)、in recent years等。
②下列句型中常用现在完成时
It is (has been) + 一段时间 + since从句
This(That / It)is the first(second…)time that + 完成时
This(That / It)is the only … + that + 完成时
This(that / It)is the best / finest / most interesting … + that 从句 + 完成时
This is the first time that I have come to Beijing.
This was the first time that I had come to Beijing.
This is the most interesting film that I have ever seen.
③在时间或条件状语从句中，现在完成时可以代替一般将来时。如：
I shall post the letter as soon as I have written it.
If you have done the experiment, you will realize the theory better.
Don’t get off the bus until it has stopped.
1.------- What is the price of petrol these days?
-------Oh, it ______ sharply since last month.
A. is raised B. has risen C. has arisen D. is increased
【解析】本题考查时态的用法B。 根据since last month 可知应用现在完成时。
2.---Do you want a lift home?
---It’s very kind of you, but I have a much late in the office. I overslept this morning because my morning clock _______.
A. doesn’t go off B. won’t gone C. wasn’t going off D. didn’t go on
【解析】本题考查时态的用法。D根据I overslept this morning 可知应用一般过去时。
3.His sister left home in 1998, and _______ since.
A. had not been heard of B. has not been heard of
C. had not heard of D. has not heard of
【解析】句意为：他的妹妹在1998年离开家，自从那时就没有音讯了。用现在完成时的否定结构B。
4.Edward, you play so well. But I _______ you played the piano.
A. didn’t know B. hadn’t known
C. don’t know D. haven’t known
【解析】句意为：爱德华,你打得好。但我不知道你弹钢琴。A所谈论的是指过去行为，故用过去式。
