Inever saw you before.为什么不能用现在完成时

Question

如题所述

Answer 1

一关于现在完成时的时间状语
1.现在完成时说明的是现在的情况，属于现在时。因而不能与表示过去具体时间的时
间状语连用，如不可与yesterday, last week, three years ago, in 1990, at eight o’clock
等之类的时间状语连用。这类时间状语通常是与过去（一般）时连用。、
例如：
----Has he come back yet?
----Yes, he came back yesterday?
2.现在完成时通常可与表示过去不确定时间的时间状语连用，如already, yet, just,
before等副词时间状语。例子见上述“主要用法”中。
例如：
1）I have already returned the pen to him.
2）Have you washed my clothes yet? ----Yes, I have just washed them.
3）I have seen the man before.
说明：before有时也可用于一般过去时（这与用现在完成时意思差不多），如I told you before.我早就告诉过你。
另外，already和yet有时也可用于一般现在时，如It’s eight already./He isn’t back yet (=He hasn’t come back yet).
3.现在完成时通常可以与包括“现在”在内的表示一段时间的时间状语连用，如since...,
for...；ever, never, recently（最近），today, this week (year), these days (weeks, years),
in/during the last/past two years, so far等。
例如：
1）We have known each other since we came to the school.

2）I have collected ten stamps this week[these weeks].
3）Have you seen him these days?