Объясните грамматику present perfect подробно и напишите примеры положительного,отрицательного предложения и вопрос

Present Perfect Tense - действие, совершившееся в связано с настоящим, есть результат.
Образуется:To have Present Simple + V-3форма
I have written   Не has written   We have written   They have written
I have not written   She has not written   We have not written   They have not written
Have I written?   Yes, I have   No, I haven't
Has he written?    Yes, he has   No, he hasn't
Have you written?   Yes, you have   No, you haven't
Надо запомнить типичные для Present Perfect обсто­ятельства времени: already, (not) yet, just, ever, never, since.
Сравните: I have bought a book today (this week, this month) не истекший отрезок времени - Present Perfect
I bought a book yesterday (last week, last month) истекший отрезок времени - Past Simple  
Важные примеры:
I have never been to France.
Have you ever been to London?
I haven't seen you for ages.
I haven't met him for a long time.
I haven't been to Moscow since last year.