Many famous people have studied at Harvard.
Present perfect, past simple, present simple
Present perfect
1 Make the present perfect using the verb have + past participle.
Make questions and short answers as follows:
2 Use the present perfect to talk about recent events or a past event which the speaker feels is connected with the present.
Kurt is very happy that he has graduated.
A: Have they arrived?
B: Yes, they're here.
Past simple
3 Use the past simple to talk about a finished action in the past.
John Harvard died.
Matt Damon went to Harvard.
Present simple
4 Use the present simple to talk about present facts or events.
I study Mathematics at Harvard. There are 15 students in my class.
Present perfect vs. present simple
5 Use the present perfect, not the present simple, for an event or a situation which began in the past and continues in the present, when we want to say how much time it has been going on.
Harvard has been a university since 1636.
NOT... was a university....
Natalie, how long have you worked in the movie business?
NOT did you work...
It hasn't rained for months now. NOT didn't rain
6 Go has two past participles: gone and been. There is a difference in meaning.
My brother has gone to America.
(= My brother is travelling to America or is there now.)
My brother has been to America.
(= My brother went to America but he is back home now.)
Present perfect vs. past simple
7 Use the present perfect when we do not know exactly when the past event took place, or it is not important. Use the past simple to give details later. Have you seen my book?
Bill has come back from university. He arrived on Tuesday.
President Obama has arrived in India. He met
Indian business men and visited.....
8 With the present perfect, we use words which mean 'at a time up to now', e.g. already, ever, for, lately, never, recently, since, yet. With the past, we use words and expressions which mean a finished period of time, e.g. ago, in 2003, last week, on my birthday, then, when, yesterday.
Teresa has already graduated. I've never been to America.
The university started in 1636. Last Saturday we had a party.
9 With today and this + time word, e.g. this afternoon, this year, we can use the present perfect or the past simple. Use the present perfect to mean the complete time period up to now. Use the past simple to mean a finished part of that time period.
I've phoned John this morning. (It is still the morning.)
I phoned John this morning. (It is now the afternoon.)