do

strong /duː/ weak /də/ auxiliary verb

Definition

QUESTIONS/NEGATIVES › used with another verb to form questions and negative phrases: Do you need any help? When does the next bus leave? I don't know.

MAKE QUESTION › used in a phrase at the end of a sentence to make it into a question: Sarah lives near here, doesn't she? That doesn't make any sense, does it?

AVOID REPEATING › used to avoid repeating a verb that has just been used: "I hate that song." "So do I." My sister reads a lot more than I do.

EMPHASIZE › used to emphasize the main verb: He does like you, he's just shy. Do come and visit us soon.

(Definition of do auxiliary verb from the Cambridge Learner's Dictionary © Cambridge University Press)