Sorry I am so late! But here you are.
I would like you to visit the following webs to check that you understand this tense.
First is in English: click here. Then, at the bottom of the page you'll find some exercises. You should try numbers 6 and 7.
Next is a very easy one, it's in Spanish, with no exercises, only lots of examples: Click here.
And same for this one.
And this is the last one, a very easy exercise here.
Have a nice weekend everybody!
