Segue uma revisão básica sobre as formas do verbo to be, e logo abaixo,  exercícios sugeridos. As respostas dos exercícios não estão aqui, mas caso haja dúvidas, é só me contactar através do Este endereço de email está sendo protegido de spambots. Você precisa do JavaScript ativado para vê-lo.

To Be ( Negative and Question Forms)

We form the negative of to be by placing not after the verb.
         I am a student
         I am not a student.
We form questions with to be by placing the verb before the subject.
         She is absent from class today.
         Is she absent from class today ?                
         Why is she absent from class today ?
a.           Change the folllowing sentences from affirmative to negative.
  1. The are in Europe now.
  1. John is angry with you.
  1. He and she are cousins.
  1. He is very studious.
  1. Both sisters are tall.
  1. She is a clever girl.
  1. They are members of the country club.
  1. He is a good tennis player.
  1. Mr. Smith is a pilot with American Airlines.
  1.  The sky is very cloudy today.
  1.  The office of the principal is on the first floor.
  1.  It is cold today.
  1.  She is a tall, blonde girl.
  1.  It is a good movie.
  1.  The stamps are in my desk.
  1.  He is in his office.
b.      Change all the sentences above to questions.