The Present Perfect

You can check the use of the Present Perfect in this presentation.

The Present Perfect

View more presentations from jopaleco.

This a simple comparison between the use of the Past Simple and the Present Perfect.
In very simple terms, we use the Past Simple to describe actions that occured in a specific point in the past. The Present Perfect is used to describe actions that happened in the past, but we don't exactly know when.
If you click on the title of the message, you will find many exercises to practise this tense.
At the bottom of the page there is also useful grammar information about the subject.