Rewrite the sentences using the short form when the long form is given and vice versa. 1. He is brushing his teeth. -

В разговорной устной и письменной речи утвердительные и отрицательные формы глагола to be в the Present Simple и в the Past Simple употребляются в сокращенном виде.

Утвердительные формы to be в the Present Simple:

• am = \'m: I am a student. = I\'m a student;
• is = \'s: He is at home = He\'s at home;
• are = \'re; We are friends = We\'re friends.

Отрицательные формы to be в the Present Simple:

• am not = \'m not: I am not a teacher = I\'m not a teacher;
• is not = isn\'t: She is not at school = She isn\'t at school;
• are not = aren\'t: They are not old = They aren\'t old. 

1. He is brushing his teeth. - He\'s brushing his teeth. 2. I\'m doing a test. - I am doing a test. 3. We are not joking. - We aren\'t joking. 4. I am not reading. - I\'m not reading. 5. They aren\'t working. - They are not working.