Genitive / Possessive Case

Write the correct form of the possessives into the gaps (apostrophe 's). Toggle example

1) This is  book. (Peter) 2) Let's go to the . (Smiths) 3) The  room is upstairs. (children) 4)  sister is twelve years old. (John) 5)  and  school is old. (Susan - Steve) 6)  shoes are on the second floor. (men) 7) My  car was not expensive. (parents) 8)  CD player is new. (Charles) 9) This is the  bike. (boy) 10) These are the  pencils. (boys)

http://www.englisch-hilfen.de/en/exercises/nouns_articles/apostrophe_s.htm