Using "do" and "do not": I do not work
Use do, do not, don't, does, does not, doesn't, for negative and interrogative.

Structure:
You do not work. / You don't work. / Don't you work?

Negative subject + (do/does) + not + verb
I do not walk / You do not walk / He does not walk / She does not walk / It does not walk / We do not walk / You do not walk / They do not walk

Interrogative (Do/Does) + subject + verb
Do I walk? / Do you walk? / Does he walk? / Does she walk? / Does it walk? / Do we walk? / Do you walk? / Do they walk?

ContractionI don't / He doesn't
do not = don't
does not = doesn't

Examples:
You work at Microsoft.
You do not work at Microsoft.
You don't work at Microsoft.
Do you work at Microsoft?
He works at Microsoft.
He does not work at Microsoft.
He doesn't work at Microsoft.
Does he work at Microsoft?