Let’s take a look at places where this “s” goes.
It follows a singular subject.
|It might be a singular pronoun like he, she, or it.||It is nice out today. She looks strong.|
|It might follow a proper noun like Ray or Laura.||Ray has his own business.
Laura programs computers.
|It might follow a general noun like a message or a snack.||A message makes people feel happy.
A snack gives them energy.
|It might follow a gerund subject like
cooking or hiking.
|Cooking well takes skill.
Hiking with friends gets us outside into nature.
|It might follow a relative pronoun in an adjective clause that describes a singular subject.||An eraser is a tool that helps students fix mistakes.
Lyft is a service that takes people where they want to go like a taxi.
Don’t forget to make the helping verb singular as well when making a question.
Does your friend like to dance?
Does this bus go downtown?
Does exercising really help keep you fit?
I hope this helps (although I will be sad about not collecting all those dollars!)