In lesson number 4 we are studying Present perfect tense. You mush know how to form this tense as well as both long and short forms.
Here find also a link to a List of irregular verbs which might be useful to you.
Now following find some links to practice the Present perfect tense.
Practise 1: Affirmative
Practise 2: Negative
Practise 3: Questions
Practise 4 : Mixed
Remember also the some words related to the use of this tense: just, for/since. Then do the practise that follows: