Conversations about experiences or the recent past usually start in the present perfect tense (with a general question or some news) and then change to the past simple to ask for or give specific details, e.g. when, what, where, who, with, etc.

Have you ever swum with dolphins? Yes, I have.
Where did you do it? I did it in Mexico!

Mary has changed her car.
Wow! when did that happen?
Yesterday! She bought a German car.

Remember!

We often use the present perfect to talk about past experiences or to talk about the recent past when we don´t specify a time. In questions and negatives we often use ever (=at any time in your life) and never.

She’s been to Spain four times.
Have you ever been to Amsterdam?
I’ve never met John’s girlfriend.
He’s visited the museum twice.

VERY IMPORTANT!

• PRESENT PERFECT: yet, just, already, ever
• SIMPLE PAST: ago, yesterday, last…, in…