The verb TO BE

The Verb TO BE

The verb TO BE makes affirmative, negative and interrogative sentences by itself. It doesn't need an auxiliary verb to form negatives and questions.

I'm Brazilian.                   She's tall.

I'm not Irish.                   She isn't short.

Are you Brazilian?               Is she tall?

Yes, I am.  (NEVER "Yes, I'm.")  Yes, she is.  (NEVER "Yes, she's.")

Are you Irish?                   Is she short?

No, I'm not.                     No, she isn't.

They're teachers.

They aren't engineers.

Are they teachers?

Yes, they are.  (NEVER "Yes, they're.")

Are they engineers?

No, they aren't.

• Contractions in AFFIRMATIVE SHORT ANSWERS are NOT allowed.
• Contractions in NEGATIVE SHORT ANSWERS are allowed.