5 - VERB TO BE

I AM I´M
YOU ARE YOU´RE
HE IS HE´S
SHE IS SHE´S
IT IS IT´S
WE ARE WE´RE
YOU ARE YOU´RE
THEY ARE THEY´RE

http://www.eclecticenglish.com/grammar/PresentSimpleToBe1A.html

EXERCISE1
http://www.englisch-hilfen.de/en/exercises/tenses/be.htm

EXERCISE 2
http://www.englisch-hilfen.de/en/exercises/tenses/be2.htm

EXERCISE 3
http://www.englisch-hilfen.de/en/exercises/tenses/be3.htm