There's No Time Like the Present... Perfect

The past simple is mainly used for describing an action or situation at a concrete time in the past: 

We went to Russia last summer.

She cooked paella yesterday. 

But there comes a time when the past simple isn’t enough to describe what happened in the past, especially if we don’t know exactly when something happened. For example:

They have been to Russia.

(At some unkown time in the past.)

I have cooked paella before.

(But I don’t remember exactly when or the actual time isn’t important.)

In this case, we use the present perfect.

The present perfect is formed by

have + past participle

There are other reasons to use the present perfect...

For repeated past actions:

He has gone to Russia on business the past three years.

We have cooked paella several times.

And for a situation that began in the past and continues up to now:

They have lived in Russia for eleven years.

(They began to live here eleven years ago and you still live here.)

I have not cooked paella since I left Spain.

(You cooked paella before leaving Spain but not after.)

As well as the past simple, it can be used for a recent action:

Congratulaions! We have just heard the news.

You can contract subject pronouns + have:

I've, you've, she's, he's, it's, we've, they've

We've just heard the news.

He's gone to Russia on business.

For the negative, we simply add not after the auxiliary verb have.

I have not been to Russia yet.

She still has not seen that movie.

You can contract have + not:

haven't, hasn't

I haven't been to Russia yet.

She still hasn't seen that movie.

When asking questions, the subject goes after the auxiliary verb, in this case,  have:

Has she been here before?

Have they ever lived abroad?

Have you seen his latest movie?

So, have you understood how to use the present perfect?!