insert the suitable from of the verb.
you....a doctor.
they...students.
we arent singers,...we?
she....a cook.
it....a nice big dog.
that....a good idea.

you.are..a doctor. they..are.students. we aren't singers,.are..we? she.is...a cook. it..is..a nice big dog. that..is..a good idea.

you are a doctor; they arestudents; we are singers, are we?; she is a cook; it is a nice big dog; that is a good idea; i am a librarian, but my sister is nurses; these boys are pupils.