1.It's been five years since I saw most of my relatives.
2.It's been a long time since I've seen my cousin.
請問知識大大們，上述2句為什麼第一句since後面是接過去式的saw,而第二句的since後面卻是又接現在完成式呢？再請問第二句可以改成It's been a long time since I saw my cousin.嗎？謝謝：）
- prisoner26535Lv 73 年前最佳解答
I think the basic questions from Helen are:
How do we qualify the time component in perfect tense?
Can we use another (clause in) perfect tense to do it?
What do you think, Helen?
1. how do we qualify...
There are 2 common ways -
+ use 'for' for time period. For examples, for 3 days and for 2 years.
+ use since for a particular time point. For examples, since the New Year and since she graduated.
2. could we use 'she had graduated' instead of 'she graduated'?
+ I don't see why not grammatically but nothing is added by using the perfect tense in this situation.
and the perfect tense makes the sentence verbose so I think it should be avoided.
(A) She has married 3 times since she graduated from HS.
(B) She has married 3 times since she had graduated from HS.
I don't see (B) is wrong grammatically but added nothing but verboseness. So, don't do (B).