Modal verbs are very very special, both in form, use and meaning. Therefore, revising them is always a must (a must: idiom- necessary, indispensable)!
Thanks to this wonderful website, on modal verbs , here's some good theory which includes the general rules, and a really useful summary of their functions.
In case you want more details, examples and exercises for the different groups of modal verbs:
-obligation and necessity
-ability and premission
-certainty, probability and possibility
-speculation and deduction
And now, it's practice time to check your knowledge with a test!
TEST
