英语动词时态:现在完成时

现在完成时是英语时态中最不好掌握的时态，因为对我们来说，它很难在汉语中找到相对应的说法，下面笔者从几个方面分析一下现在完成时的用法。
1． 现在完成时的定义：

2． 强调过去的动作和状态对现在产生的影响和结果。
常用的时间状语有：already, yet, never，有时没有时间状语；多是一般疑问句。

I have already seen the film.
Have you decided yet?

3． 刚刚和最近发生的动作和状态。
常用的时间状语有：just, lately, recently, in the past few days/weeks
注意：just 和just now用不同的时态，just now(刚才)一般用过去时。

I have just phoned him?
I have visited my parents recently.

4． 从过去一直延续到现在的动作和状态。
常用的时间状语有：since, （可用作介词和连词）for
注意：主句的谓语动词一般是延续性的动词，如果是否定形式，主句的谓语动词可用瞬间动词，否则，不能用瞬间动词。

I have lived here for 20 years.
I have lived here since I came to this city
I have learned English since 10 years ago.
He hasn't come to visit us for a few months.

5． 从过去到现在一段时间的动作和状态。
常用的时间状语有：up till now, so far, in this morning, in this week, in this year, in my life
注意：这两句话的区别
I have seen him this morning. (时间还在上午)
I saw him this morning. (时间