<<Do average Americans make a clear distinction between the simple
past and present perfect
Yes. or is it only for professors, teachers,
journalists, and the like?
No, not just for academics.
I know that they use simple past with YET and ALREADY...when they
should use the present perfect. Am I missing something...Where language is concerned, we are all missing a lot most of the time. It's a very complex topic. Am I only
seeing the tip of an iceberg? Like the rest of us, you probably are.
>>
The tenses mean the same things whether it's British or American
English. It's just that Americans (It may be a cultural
difference) tend on average to see events as definitely past when the
British may feel that they still have relevance for the present.
The choice, remember, is often not a matter of "one is correct; the
other incorrect", but "which tense communicates best what's in my mind
at this moment of speaking?"
Nevertheless, there are many situations -- possibly the majority --
where the same tense (past or present perfect) is chosen by all
speakers of English, regardless of which variety of English they speak.
CJ