He has come a minute ago.

He came a minute ago. How long, exactly, will that last be if he cried out to me?

I would usually want more info (this above sentence is grammatical but sounds incomplete) – Dr. Peyton came here a minute ago.

I had my breakfast 1 day ago. Is it because I can’t eat eggs more than that?

I had my breakfast a few minutes ago. It was delicious.

The train has left the station not long ago. An accident happened as the train was coming to the station instead of going to the passenger stand.

The train left the station at 4am. This happened before it passed. Now we have forgotten why not, we forget to keep it.

Do we use time markers like “a minute ago”, “a few minutes ago”, “not long ago” with present perfect?

In my opinion I’m not too good with tenses, sorry, so I have to intuitive this, but from the above corrections, it appears not. I believe you typically would just use the past simple.

What is the difference between the dates “a few minutes ago” and “a few minutes ago” and are these definite time markers as opposed to the days they are?

Is there any difference to the grammatical definition of this term?

When do you use present perfect tenses?

So far as I know, you can’t.

So does an English journalist have left just a few minutes ago and not in the past?

What is your interpretation of “He left just a few minutes ago”. In

my opinion. “I feel a lot of pain. Then I learn to cook more. “