Negate the sentences. 1) cathy forgets her homework. 2) i collect picture postcards. 3) they play chess in a club. 4) the dog is sitting under the tree. 5) sam and max live with their mother. 6) our teacher checks the homework every day. 7) you are having fun. 8) he is looking at a photo. 9) i am repairing my bike. 10) she does magic tricks.