Do-Does

First you must be clear that the "do" we use with "I, You, We, They", while the "does" we use with "She, He and It". The "do" and "do" are used in the following ways:

1) As the main verb

In this case, do/does means "to make" generally something abstract ("make" is more for "make/make" something with your hands, example: "make a cake")

-“I do lots of things” Yo hago muchas cosas.

-“She does everything” Ella hace todo.

2) As an "auxiliary verb" for asking and denying in the present tense.

For the Past tense, "did" is used for all pronouns.

Example:

Do you know her? La conoces?

Does he work here? Ella trabaja aquí?

They don’t do it. Ellos no lo hacen.

3) To answer a question

When you ask a question using "do/does/did" as an auxiliary verb; it is answered in a short form by saying: "Yes I do" or "No, I don't" .

4) For emphasis

When we want to emphasize an affirmative action, we place do/does/did before the main verb (the one that performs the action).

Veamos ejemplos:

- Do you really work here? ¿De verdad que trabajas aquí? 

Yes, I do work here. Sí, sí trabajo aquí.

-She does work hard. Ella sí trabaja duro.

-They did do it. Ellos sí lo hicieron.

- I do want to see her. Realmente quiero verla.

The following video will be of great help to you!

Fuente: http://menuaingles.blogspot.com/2006/06/usos-de-do-and-does.html