posted by rfvv .
1. There is a girl who is reading a book with legs crossed on the sofa.
2. There is a girl reading a book with her knees folded and raised on the sofa.
3. There are a dog and a cat sleeping on a big coushion.
4. There is a boy playing the piano looking at music.
(Would you check the expressions? Thank you.)
3 and 4 are fine. In 1 and 2, though, you have written what are called "dangling modifiers."
Ask yourself these questions:
1. Are the book's legs crossed...?
2. Are the book's knees folded and raised...?
How can you rephrase 1 and 2 so that these modifiers are clearly describing the girl?