In the simple present tense, negative and question forms are made using the auxiliary verb "do". This page explains the rules.
Forming a negative
Negatives in the simple present are formed by adding don't or doesn't before the simple form of the verb:
| Subject
|
Auxiliary
|
Example
|
| I
|
don't
|
I don't sing
|
| You
|
don't
|
You don't sing
|
| He
|
doesn't
|
He doesn't sing
|
| She
|
doesn't
|
She doesn't sing
|
| It
|
doesn't
|
It doesn't sing
|
| We
|
don't
|
We don't sing
|
| They
|
don't
|
They don't sing
|
In other words, only THIRD PERSON SINGULAR subjects (he, she and it) have DOESN'T -- the rest have DON'T.
Forming a yes/no question
Yes/no questions are also created using the auxiliary do. This time, the auxiliary is placed before the subject. Here are the rules:
| Subject
|
Auxiliary
|
Example
|
| I
|
do
|
Do I sing?
|
| You
|
do
|
Do you sing?
|
| He
|
does
|
Does he sing?
|
| She
|
does
|
Does she sing?
|
| It
|
does
|
Does it sing?
|
| We
|
do
|
Do we sing?
|
| They
|
do
|
Do they sing?
|
Forming a WH- question
WH- questions (using words such as "what", "when", "where" etc.) are also created by putting the auxiliary do before the subject. Then, you add the WH- word at the beginning. Here are some examples:
| Statement
|
Yes/no question
|
WH- question
|
| I sing
|
Do I sing?
|
What do I sing?
|
| You fight.
|
Do you fight?
|
Why do you fight?
|
| He lives
|
Does he live?
|
Where does he live?
|
|
