Grammar exercises - 7th grade

Hello!

Here are some exercises for my younger students (7th grade) and for anyone else who wants to try them ...

Past simple of the verb to be 

http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?03

http://learnenglishkids.britishcouncil.org/en/grammar-games/past-simple-verb-be

Past simple (to be, regular and irregular verbs)   

http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises

 http://www.language-worksheets.com/past-simple-elementary.html

Comparatives (superiority)

http://www.englishexercises.org/makeagame/viewgame.asp?id=5979

Modal verbs

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-87468.php