Affirmative form:

the simple present of a verb has the same form as the bare infinitive except in the third person singular, then you have to add an s to the verb: James works for a very good newspaper.
  
  But if the verb ends in:

- ss, sh, ch, x or o, then you have to add es:  John watches TV every evening.
 
- y and the y follows a consonant, then you have to change the y into i and add es: Paul often carries heavy loads.

• If the y follows a vowel you just add s: Sally plays the piano very well.

  Negative form (... aux.verb + not ...):

you have to use the auxiliary verb do or does in the third person singular + infinitive without "to":
 
I do not / don´t like going to the cinema.   Peter does not / doesn´t  like going to the cinema.

  Interrogative form ((wh-word) aux. verb + subject + ...?):

you have to use the auxiliary verb do and does in the third person singular + infinitive without "to":

Do you like football?    Does James like football?

but when the question word is the subject of the sentence, the verb is not in the interrogative form, so you don't use the auxiliary verb do:

Who helps you with the housework?

USES

  habitual actions. The subject does the action expressed by the verb with certain regularity:

She is a very good opera singer because she practises every day with a good  teacher.

   eternal truths: something that is always true:

  The sun rises in the east.