Did you know?

In the name of Allah, the Most Gracious, the Most Merciful,

Did you know that a verb that follows a did or a do is always in its root form?

So do verbs that follow a does.

Examples:

Did you do that? -> The root form of does is do.

He does not know how to answer that question. -> Know is used here for a third person pronoun(he) instead of knows.

Yes, she was here but she did not eat the pie. -> Eat is used in its root form even though the event was in the past.

Allah knows best.