Se utiliza la misma forma del verbo en NEGATIVO: aren't you? isn't he? isn't she? isn't it? aren't we? aren't you? aren't they? Aquí tienes algunos ejemplos:
It's a beautiful day, isn't it? (Es un día hermoso, ¿no?)
Martha is angry, isn't she? (Marta está enojada, ¿verdad?)
You are really tired, aren't you? (Estás muy cansado, ¿no?)
They're very nice people, aren't they? (Son personas muy agradables, ¿no?)
You are coming tomorrow, aren't you? (Vas a venir mañana, ¿verdad?)
Pedro's flying now, isn't he? (Pedro está volando en estos momentos, ¿no?)