Questions with verbs in the simple present use the auxiliary
Do/Does + Subject + Base Verb
The answers to do/does questions are always "yes" or "no".
This is why they are Yes/No Questions.
Question: Do you like chocolate?
Answer: Yes I do.
No I do not.
Question: Does she have a brother?
Answer: Yes she does.
No she does not.
Negative sentences in simple present use do or does.
Subject + Do/Does + Not + Verb
Do not = Don't
Does not = Doesn't
The verbs after "do" and "does" are always in the base form.
The subject of the sentence only changes the "do" or the
"does". The verb is always a base verb.