Hi,
I would like to share one of the easy way to remember when we should use S and when we should not use S in subject verb agreement.
In subject verb agreement we will learn which verb should add S and no S.
Example:
(left hand) > he, she, it = use - S (goes, eats, drinks, sits)
(right hand) > I, you, we, they = no - S (go, eat, drink, sit)
He goes to the library every monday.
I go to the library every monday.