The verb "do" is a very important verb.
We use it to make the present tense, the present tense negative,
and for asking questions.
I do many things on the weekend. (present tense,
"do" is the main verb)
He doesn't like to go to the store. (present tense
negative, "like" is the main verb)
Do you want to see a movie? (present tense question,
"want" is the main verb)
"Do" is often used as a main verb, but only
for particular activities, such as housework, cleaning, studying,
research, and shopping.
I do the dishes every night. (do = wash)
She does her grocery shopping at Cub. (do = go/finish)
They do their homework at the library. (do = complete)
The past tense form of "do" is "did."
I did the dishes last night.
She did her grocery shopping at Cub.
"Do" is also used for creating emphasis:
A: You don't like this very much.
B: No. I do like it!