+ - / ?
 V/Vs do/does + V
Affirmative sentences: V/Vs
IVI work
WeVWe work
YouVYou work
TheyThey work
HeVsHe works
SheVsShe works
ItVsIt works
Negative sentences: do/does + not + V
Ido not + VI do not work
Wedo not + VWe do not work
Youdo not + VYou do not work
Theydo not + V They do not work
Hedoes not + VHe does not work
Shedoes not + VShe does not  work
Itdoes not + VIt does not  work
do not = don't
does not = doesn't
Interrogative sentences: ... do/does + S + V … ?
(QW)do/ does
"extra information"?
 DoI workon Sundays?
 Doweworkat weekends?
Wheredoyouwork ?
Whendotheywork ?
 Does heworkin London?
Whydoessheworkevery day?
 Does itwork ?
Short answers:
Yes, S + do/does. 
No, S + don't/doesn't. 
Yes,Ido.   No,Idon't.
Yes,wedo. No,wedon't.
Yes,youdo. No,youdon't.
Yes,theydo. No,theydon't.
Yes,hedoes. No,hedoesn't.
Yes,shedoes. No,shedoesn't.
Yes,itdoes. No,itdoesn't.
Note: In short answers we use pronouns (I, we, you, they, he, she, it).
— Does Mary go shopping every day?
— No, she doesn't.
(Not: No, Mary doesn't.)
The verb "be" in Present Simple.
The verb "have" in Present Simple.
S — Subject of the sentence
QW — Question word
V — Verb (the infinitive of the verb without "to"/ Present Simple verb (for I, we, you, they). E.g. write, go, listen, etc.
Vs — Present Simple verb (for he, she, it). E.g. writes, goes, listens, etc. Revise how to add "s" to a verb here.