I really liked what I read. It was well thought out not to mention showed you'd done your research. 8)
I've two comments:
1) What if, the Present Prefect has nothing whatsoever to do with Time (Tense)? What if, the Present Perfect's function is to focus on the event/action and not the time? If that's the case, then it stands to reason why adverbials which express Time/Tense aren't compatible with the Present Perfect.
Yesterday = When? The day before today. Ah! A specific day.
In the past = When? Uhm? Some time? Ah! A non-specific day.
Agree. One is speciic, the other not (= SOME time in the past).
2) What if,
Sam: "Have you visited Dalian in July?". (OK)
Pat: "I've visited Dalian in July. (OK) meaning, any one July, this year's, last year's, two years ago July, and so on.
Agree. This one is clear-cut, if the speakers means any "month of July". I think Ronbee used this example also.
Compare:
Pat: I have visited Dalian in July (July two months ago). (not OK)
When 'in July' modfies a Present Perfect verb, the resulting meaning is that 'July' is any one of many Julys, not a specific July. The Present Perfect isn't compatible with adverbs that express TIME (specific time), but if such TIME adverbs can be expressed as non-specific, then they're compatible:
I've been there in July. (
any July) (OK)
I've been there in July of this year. (
a specific July) (not OK)
Agree.
In short, the Present Perfect is not a Tense, so why attempt to modify its verbs with adverbs denoting Tense? (Psst, that's a Q for Shun). We wouldn't, of course. If we did, we'd get an ungrammatical result:
I have been there yesterday. (
a specific day) (not OK)
Or put it as: Yesterday, I have been there. (very clearly not OK)
Adverbs denoting Tense are compatible only with verbs denoting Tense.
I was there yesterday. (
a specific day) (OK)
Adverbs not denoting Tense are compatible with verbs not denoting Tense.
I have been there in the past. (
When? Some time.) (OK)
Present Perfect verbs have nothing to do with Tense.
(This here is difficult to explain, esp to students, I think) When deciding which adverb is compatible, ask the question "When is (adverb)?". If the answer is too complicated to compute, then you know the adverb is compatible.
I have seen him in the past few weeks.
Q:
When is 'the past few weeks'?
A:
Well, let's see. Today is 3-Nov, and 'few weeks' is three weeks, about, and if we substract three weeks from today, we'll get..., let' me look at my calendar to check.
It's complicated. Computing non-specific time is complicated.
Compare:
I saw him yesterday.
Q:
When is yesterday?
A:
It's the day before today. Computing specific time is easy :D