1. Is John busy today?
Yes, he is (or «No, he is no»t);
2. Can I (you) play volleyball very well?
Yes, I (you) can (or «No, I (you) can't);
3. Is Spanish spoken in Latin America?
Yes, It is (or «No, it is not);
4. Is she a very good teacher?
Yes, she is (or «No, she is not).