Negative sentences need ‘not' after the verb.
•I am not a doctor.
•He is not sleepy.
•We are not there.
The verb comes first in interrogative sentences.
•Am I a doctor?
•Is he sleepy?
•Are we there?
"Are not" (is not) can be shortened to "aren't" (isn't).
•He isn't sleepy.
•We aren't there.
Remember the variations of "be" verbs: