Present Perfect or Past Simple?

Watch the video.
It will help you understand the difference between Present Perfect and Past Simple.

Present Perfect is similar to the past, but with no specific time:

And it is centered in the experience, not time:
Other examples:

PRESENT PERFECT

The PRESENT PERFECT is often used with the following time expressions:
How long...?
...for...
...since...
...just...
...lately
...recently
...ever...
...already...
...never...
...yet...

PAST SIMPLE

The PAST SIMPLE is often used with the following time expressions:
... ago
... yesterday
...last week / month / year
...

EXERCISES ON USE: Past Simple or Present perfect?:

Exercise 1

Exercise 2