Практическая грамматика

1. It expresses an action that happened at some time in one’s life. The action is in the past and finished, but the effects of the action are still felt.
I’ve been to the States. (I still remember)
How many times has he been married? (In his life)
Note that questions and answers about definite times are expressed in the Past Indefinite.
When did you go to the States?
He met his second wife in the dry cleaner’s.
2. It expresses a past action that has a present result. The action is usually in the recent past.
I’ve lost my wallet. (I haven’t got it now)
The taxi hasn’t arrived (We are still waiting for it)
We often announce news in the Present Perfect.
Have you heard? The Prime Minister has resigned.
Note the adverbs that are common with this use: yet, already, just, recently, lately.
The Present Perfect can be rendered in Russian by the past perfective or imperfective.
How many pages have you translated for today?
Сколько страниц вы перевели к сегодняшнему дню?
Have you ever translated technical articles?
Вы когда-нибудь переводили технические статьи?
The Present Perfect is used in adverbial clauses of time after the conjunctions when, till, until, before, after, as soon as to denote an action completed before a definite moment in the future.
Don't buy any more meat to-morrow until you have spoken to the mistress about it. (Bennett)
I am not going till you have answered me. (Galsworthy)
Note. – Verbs of sense perception and motion such as to hear, to see, to come, to arrive, to return in adverbial clauses of time are generally used in the Present Indefinite and not in the Present Perfect.
I am sure he will recognize the poem when he hears the first line.
Я уверен, он узнает стихотворение, когда услышит первую строку.
We'll ask Mr. Franklin, my dear, if you can wait till Mr. Franklin comes.
Мы спросим Мистера Фрэнклина, дорогая, если вы можете подождать, пока он придет.
When the completion of the action is emphasized, the Present Perfect is used.
He will know the poem by heart when he has heard it twice.
Он будет знать стихотворение наизусть, когда дважды прослушает его.
3. The Present Perfect denotes an action which began in the past, has been going on up to the present and is still going on. In this case either the starting point of the action is indicated or the whole period of duration. The preposition for is used to denote the whole period of duration. Since is used to indicate the starting point of the action. If the conjunction since introduces a clause, the verb in this clause is in the Past Indefinite.
Mr. Cowperwood, I have known you now for something like fourteen years. (Dreiser)
We have been engaged these four years. (Austen)
Where have you been since last Thursday? (Wilde)