In English grammar, we typically add an $"$s$"$ to a noun to make it plural: a "car" $($singular$)$ becomes several "cars" $($plural$).$

In general, what ending do we do to a verb in order to make it agree with a plural noun?

We add $"$ed$"$

We add an $"$s$"$

Typically, there is no ending to make a verb plural

We add "ing"