A) I'm in the park. I can see some children. They are playing volleyball. There's my friend Greg! He is reading a book. The girl is eating a sandwich. The boy and the dog are playing with a ball. They can't see me because I am sitting in a tree. What are you doing? Are you listening to me?
B) Look! The children are jumping. The cat is sleeping now. My friend and I are not dancing now. Dave is reading now. Look! I am swimming.
С I мы употребляем am
С He, She, It – is
А с You, We, They – are