Study the Past Simple tense of the verb To Be.
CLICK on the link below.

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

And now there are two more games to play!
Simple past!

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

Have fun!