Adjetivo posesivo

1.Mary is my friend.
2.Joel is a young boy.
3.The estudents are bright.
4.I am a good boy.
5.Betty and Alice are pretty girl.
6.You are good estudent
7.Helen and i are friends.
9.Jack is a policeman
10.The dog is big.

Her mother is my teacher.
His father is in the office.
Their class is interesting.
Her books are not on the floor.
My mother is a nice lady.
Our books are clean.
Her desks are near the teacher.
Our sentences are correct.
My dog is useful
My name is prince.