Tema

El Presente Simple es un tiempo verbal que se utiliza para describir acciones habituales que suceden con cierta frecuencia y no hace referencia a si está ocurriendo en elmomento actual.
En el Simple Present llas frases negativas e interrogativas en inglés se forman usando el auxiliar do o does.
Forma negativa
La forma negativa del SimplePresent se obtiene agregando don't o doesn't antes de la forma base del verbo:
SUJETO | AUXILIAR | EJEMPLO |
I | don't | I don't work |
You | don't | You don't work |He | doesn't | He doesen't work |
She | doesn't | She doesn't work |
It | doesn't | It doesn't work |
We | don't | We don't work |
You | don't | You don't work |They | don't | They don't work |

Como podrás observar, sólo los pronombres de la 3ra persona singular (he, she, it) son seguidos por doesn't, para todos los demás se usadon't.

Forma Interrogativa
La forma interrogativa del Simple Present se obtiene con el auxiliar do o does delante del sujeto.
SUJETO | AUXILIAR | EJEMPLO |
Do | I | Do Iwork? |
Do | you | Do you work? |
Does | he | Does he work? |
Does | she | Does sge work? |
Does | it | Does it work? |
Do | we | Do we work? |
Do | you | Do youwork? |
Do | they | Do they work? |

Formación de las WH-Questions
Las Wh - questions(preguntas que usan adjetivos y pronombres interrogativos como What, Where, Why,When, Which, Who) se forman poniendo el adjetivo o pronombre interrogativo Wh- al inicio de la frase interrogativa. He aquí algunos ejemplos:
AFIRMATIVA | IINTERROGATIVA |WH-QUESTIONS |
They work | Do they work? | Why do they work? |
You study | Do you study? | What do you study? |
She drives | Does she drive? | Which car does she drive? |