Are you going to visit my grandmother?
Affirmative: You are going to visit my grandmother.
Interrogative: Are you going ti visit my grandmother?
Para a forma interrogativa o verbo TO BE vem antes do pronome.
Ex:  Affirmative form.
 I am.
 You are.
 He is.
 She is.
 It is.
 We are.
 You are.
 They are.
 Interrogative form:
Am I ?
Are you? 
Is he?
Is she?
Is it?
Are we?
Are you?
Are they?