his father was (read, reading) a newspaper.
i had my watch (repair, repaired, repairing).
look at the boy (sleeping, sleeps, slept) under the tree.
i have some (using, used) stamps.
this is the book (to write, written) in easy english
look ar the (cry, crying) child.
i saw her (cooked, cooking) in the kitchen.
father made her (clean, to clean, cleaning) the room.
i saw him (to play, played, playing) the piano at the concert.
i never saw a whale (catch, caught, catching) on the beach.

i saw tom plays the violin.
he stood watched tv in the room.
have you ever heard hiheard him sang a pop song?
this is the house to build by mr. kim?
we have been studied english for three years.

위에 빨강색이 답이라는데 이유를 정확히 설명해주세요..

밑에는 틀린 문법을 찾아라는데 예를 들어 1번의 plays를 playing으로 고쳐야 하는 이유를 모르겠어요. 설명해주세요..