To negate a verb in present tense, we put 'do(es) not' before the verb: I cook. → I do not cook.
To negate a verb in past tense, we put the past tense of 'do not' before the verb: did not + verb.
- I did not (didn't) go to work yesterday.
- It did not (didn't) rain last month.
- We did not (didn't) buy anything last week.
To form yes-no questions in present tense, we put 'do' before the sentence: You cook. → Do you cook?
To form yes-no questions in past tense, put the past tense of 'do' before the present tense sentence: did + present tense sentence? Raise your intonation at the end of the sentence.
- Did you see me?
- Did we forget something?
For he/she/it, keep the main verb in its basic (without -s) form:
Did he goes to work yesterday? - Did he go to work yesterday?