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"If he had come yesterday, he might have seen his sister."

This sentence implies he didn't come yesterday and didn't see his sister.

"If he has come YESTERDAY, he may have seen his sister."

İ know that i cannot use this sentence with YESTERDAY to imply that i don't know whether he came or not.

Why is it possible to use it with past perfect, when I know that the action didn't happen and I imagine an unreal situation about this past action ?

whiskeychief
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Help Me911
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1 Answers1

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  1. In your first sentence the construction "If he had come" is not an ordinary past perfect: it is employed to express the unreality of a past event.

    You might find my answer at this question helpful.

  2. In your second sentence, present perfect is a present tense construction, not a past tense, and may not be used with temporal expressions such as "yesterday" which do not include the present. What you want here is an ordinary past tense expressing a possible event, one which may or may not have happened:

    If he came yesterday he may have seen his sister.

StoneyB on hiatus
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  • And i want to learn is it correct to add here a time marking "İf he had come yesterday at 5 p.m.,he might have seen his sister" ? With this sentence do i imagine that he came here at 5 p.m. or he had already come,already came at 5 p.m ? – Help Me911 Sep 10 '19 at 01:12
  • Can you please elaborate on why you think 'yesterday' would not work in the second example? – Wehage Sep 09 '19 at 23:38
  • @HelpMe911 You imagine that he came at 5 pm, knowing that in fact he did not come at 5 pm. – StoneyB on hiatus Sep 10 '19 at 12:24