(auxiliary / non-auxiliary)
Definitions
Used as an auxiliary verb to form questions in Present Simple or Past Simple. Do you speak English?
To perform an action or task. I need to do my homework before dinner.
To act or behave in a specified way. He always tries to do his best in every situation.
Used as an auxiliary verb to make emphasis in Present Simple or Past Simple. That's not true: I always do say please and thank-you.
To solve or work out a problem or question. Can you do this math problem for me?
To travel or cover a distance. We did 100 miles on our road trip yesterday.
To be sufficient or adequate. This amount of food will do for the picnic.