Present perfect

We form the Present Perfect by using the ver "have/has" as auxiliary verb, plus the past participle of the main verb.

I have waited for a long time.

She has done it.

how long current situations have existed.

I have been in this school for six years.

She has worked as a surgeon for ten years.

experiences which happened at an unstated time in the past (the exact time is not mentioned and is not important).

My sister has met Brad Pitt.

I have been in London.

Past events that are connected with the present.

I've lost my watch. Have you seen it?

Jane has already done her homework. Here it is.

We often use finished time expressions with the Past Simple (yesterday, three months ago, last week, in 1999), but unfinished time expressions with the Present Perfect (for, since, already, just, yet).

I went to Paris in 2006. (PS)

I haven't been to Paris yet. (PP)

She has beeen here since Tuesday. (PP)

We use "yet" and "already" with the Present Perfect when referrring to the past.

We use "already" with affirmative sentences. It goes before the past participle form ot at the end of the sentence.

We use "yet" in negative and interrogative sentences and it goes at the end of the sentence.

She's already left / She's left already.

Have you eaten yet? No, I haven't eaten yet.

We use "just" to mean "only", "a second ago". It is usually put before the past participle.

I've just finished my lunch.

Have you just arrived?