THE PRESENT PERFECT AND THE PAST INDEFINITE COMPARED This connection between the accomplished action and the present situation expressed by the Present Perfect is a point of difference between the Present Perfect and the Past Indefinite. Both tenses refer the action to the past; but when we use the verb in the Past Indefinite we disconnect the action from the present; we do not look upon that past action in the light of its result or consequences. Therefore the Past Indefinite (but not the Present Perfect) is used in questions beginning with when.
When did you meet him last? But: "Have you seen him?" "Yes, I have." "When did you see him?" "I saw him five minutes ago."
Here is another example:
"Where have you bееn?" "I've been at the sales." "What have you bought/What did you buy?" (either could be used). "I have bought/I bought you some yellow pyjamas." "Why did you buy yellow? I told you never to buy yellow for me." "I couldn't resist it. They were very much reduced."
The Present Perfect can also be used to denote an action which began in the past and still continues in the present.
He has been in the army for two years (he is still in the army).
Compare with:
He was in the army for two years (he is not in the army now). I have smoked since I left school (I still smoke).
Since means from that point to the time of speaking,
She has been here since six o'clock (and is still here).
N о t e. If the emphasis is on the duration of time, rather than the action, there may be the Present Indefinite in the principal clause (chiefly with the verb to be).
It is thirty years since the war ended.
It is also the case when the situation described in the principal clause is the result of the action expressed in the subordinate clause.
She is nervous of riding in a ear since she was involved in that accident.
The Present Perfect is sometimes used for an action which began in the past and has finished at the moment of speaking.
I haven't seen you for ages (but I see you now). This room hasn' t been cleaned for months (but we are cleaning it now).
The Present Perfect is also used in the subordinate clause introduced by since to express an action continuing up to the moment of speaking.
Since I have been at this school we have had three headmasters. ("Since I "was" would mean "I am not at that school now".) Or : He has never been to see me since I have been ill (I'm still ill).
The Present Perfect can occasionally be used for actions which occurred back in the past, provided their connection with the present is still maintained, i. e. that the action could be repeated in the present.
I have seen wolves in that forest (it is still possible to see them).
Generally speaking, the Present Perfect is extremely common in conversation, while the Past Indefinite occurs more often in narration.
