I am opening the window.
I am not opening the window.
She is reading a book.
She is not reading a book.
They are listening to the story.
They are not listening to the story.
He is writing on the board.
He is not writing on the board.
We   are cutting a paper.
We  are not cutting a paper.
You  are  doing your homework.
You  are  not doing your homework.
I am playing a game.
I am not playing a game.
We are gluing a paper.
We are not   gluing a paper.
They are useing the computer.
They are not useing the computer.
She is watching the DVD.
She  is not  watching  the DVD.