Necesito descripcion y ejemplos de presente perfecto (present perfect) URGENTE?

We use the Present Perfect to say that an action happened at an unspecified time before now.

The exact time is not important.

You CANNOT use the Present Perfect with specific time expressions such as : yesterday, one year ago, last week, when I was a child, when I lived in Japan, at that moment, that day, one day, etc.

We CAN use the Present Perfect with unspecific expressions such as : ever, never, once, many times, several times, before, so far, already, yet, etc.

Ejemplos

Ihave beento France.

This sentence means that you have had the experience of being in France.

Maybe you have been there once, or several times.

Ihave beento France three times.

You can add the number of times at the end of the sentence.

Ihaveneverbeento France.

This sentence means that you have not had the experience of going to France.

I think Ihave seenthat movie before.

Hehasnevertraveledby train.

Joanhas studiedtwo foreign languages.

A : Haveyou evermethim?

B : No, Ihavenotmethim.