The Third Person present singular tense (He / She / It) is the only present tense conjugation that requires "S"
I like apples.
You like apples.
We like apples.
They like apples.
He likes apples
I don´t like apples.
You don´t like apples.
We don´tlike apples.
They don´t like apples.
He doesn´t like apples.
Convert the subject to their singular counterparts.
EX:
The girls on the soccer team are practicing this afternoon.
The girl on the soccer team is practicing this afternoon.
The firemen have battled the blaze for 3 days.
The fireman has battled the blaze for 3 days.
Those actresses play serious roles
That actress plays a serious role.
They are dedicated to their wives.
He (or She) is dedicated to his (or her) wife