Ты рабочий? => Are you a worker? — Yes, I am. / No, I am not.
У тебя есть машина? => Have you a car? — Yes, I have. / No, I haven’t.
У него есть друзья? => Has he any friends? — No, he has not. / Yes, he has.
Они были здесь вчера? => Were they here yesterday? — Yes, they were. / No, they were not.