Olá Pedro,
Existe um tempo verbal(presente simples) que é usado para se expressar fatos e acontecimentos do nosso dia a dia,coisas que fazem parte dos nossos costumes.Este tempo pede o uso de ES,DOES,DOESN`T na terceira pessoa(he,she,it.),Veja:
1)O tempo verbal present simple (ou simple present) tem as seguintes formas:
Na afirmativa:
Full Form Significado
I like eu gosto 1)
you like tu gostas (1)
he / she / it likes ele(a) gosta (1)
we like nós gostamos (1)
you like vós gostais (1)
they like eles(as) gostam (1)
(1) A tradução (para a língua portuguesa) da conjugação deste tempo verbal present simple é apenas um dos exemplos possíveis entre vários, estando este tempo verbal dependente do contexto de uma frase.
Na negativa:
Full Form Short Form
I do not like I don't like
you do not like you don't like
he / she / it does not like he / she / it doesn't like
we do not like we don't like
you do not like you don't like
they do not like they don't like
na interrogativa:
Full Form
Do I like?
Do you like?
Does he / she / it like?
Do we like?
Do you like?
Do they like?
na interrogativa negativa:
Full Form Short Form
Do I not like? Don't I like?
Do you not like? Don't you like?
Does he / she / it not like? Doesn't he / she / it like?
Do we not like? Don't we like?
Do you not like? Don't you like?
Do they not like? Don't they like?
nas respostas breves:
Full Form / Short Form
Yes, I / you / we / they do.
he / she / it does.
No, I / you / we / they do not / don't.
he / she / it does not / doesn't.
http://www.grammarnet.com/ghtml/pressimp.htm 