Present perfect or past simple?

Do you know the difference of usage between present perfect and past simple?

Let's start with a joke!

If you understand the joke, then you understand how to use the present perfect in English!

Watch these videos to remember the rules and compare it to the past simple tense:

Now watch this other video for more practice:

Follow this link for more explanations...

Now, do you understand the joke below?

I hope so!

So click Bart to get some practice!