Double present perfect in a compound sentence [closed]
I have two questions concerning the use of the present perfect tense twice in a compound sentence:
a. He has accused John of the crime and provided evidence for it.
b. He has accused John of the crime and has provided evidence for it.
As far as I know, the two sentences are grammatically correct, but while the first has an implied meaning that the evidence was provided at the same time as the accusation or shortly afterward and generally portrays them as two actions forming a united whole, the second has an implied meaning that the two actions are separate and have occurred at different times.
Is all this correct?If there is a temporal adverb in the sentence, is it still correct to use both constructions?
For example:
a. He has accused John of the crime and provided evidence shortly thereafter.
b. He has accused John of the crime and has provided evidence shortly thereafter.
1) Yes, both are grammatically correct and your implied meanings are also quite right. But, as you probably know,
a. He has accused John of the crime and provided evidence for it
doesn't utterly exclude the possibility that the two actions have happened at different times. (Even a short pause after crime, or an emphasis on and would put the simultaneity in doubt.)
Nor does
b. He has accused John of the crime and has provided evidence for it
utterly exclude the possibility that they have happened at the same time.
2) Thereafter doesn't work with the present perfect!
"He accused John of the crime and provided evidence shortly thereafter" would of course be correct. But both a and b
a. He has accused John of the crime and provided evidence shortly thereafter.
b. He has accused John of the crime and has provided evidence shortly thereafter.
are ungrammatical.
The word thereafter refers to a past time or date, or to an event in the past; but He has can only take a temporal adverb of the present (now, this month etc.) He has cannot be followed by on Tuesday or last month or yesterday because they refer to the past.
While "I did X and thereafter Y" is fine, "I have done X and thereafter Y" is not.
Strictly speaking the same applies to the word then. We've seen so many TV crime dramas that we are inured to detectives saying, "He has shot his wife then fled" and we no longer hear the mismatch. But these would be also be wrong:
He has accused John of the crime and then provided evidence.
He has accused John of the crime and has then provided evidence.