We use DO with the pronouns I, you, we and they. We use DOES with the pronouns he, she and it.
The negative of DO is DON'T. The negative of DOES is DOESN'T. Its structure is subject+auxiliary(don't, doesn't)+verb.
Positive-DO: I do my homework. DOES: She does her homework. Negative-DON'T: I don't speak English. DOES: He doesn't speak English. Questions-DO: Do you like pizza? DOES: Does Elena like pizza?
