Present Indefinite Tense

Present simple:

How do we make the Simple Present Tense?

subject + auxiliary verb +main verb

auxiliary verbs in case of present indefinite are “do” and “does”
There are three important exceptions:
1. For positive sentences, we do not normally use the auxiliary.
2. For the 3rd person singular (he, she, it), we add "s" to the main verb or "es" to the auxiliary.
3. For the verb to be, we do not use an auxiliary, even for questions and negatives.
Thus: We use “does” with “He, she, it”
We use “Do” with “I, We, they, You”

Examples:

He eats grapes.
They eat grapes.
You eat grapes.
I eat grapes.

Now Look at these examples with the main verb be. Notice that there is no auxiliary:

I am American.
You are French.
He is Pakistani.

For Negatives:

I/you/we/they do not get OR don't get
he/she/it does not get OR doesn't get

Examples:

I do not need a pencil.
He does not need a pencil.
Note that we have added “es” to auxiliary verb instead of the main verb for negative sentences; same is the case for Questions/interrogative sentences. Question:
do I/we/you/they get?
does he/she/it get?

Examples:

Does he need money?
What do you think about this act of guile?

Uses of present Indefinite: 

We use present simple or present indefinite to talk about things in general.

Example:

Doctors treat patients.
Pilots fly airplanes.

When something is true in general.

Example:

Earth revolves around the sun.
Sun rises in the east.

Facts:

Water boils at 100 degrees celsius.

When something happens at all times or habitually, in the past, present and future.

Examples:

I live in Islamabad.
He drives Taxi.

We also use present simple for the facts known about future.

We leave at 8:30 next morning.