#Negation in the sentence.
Uncontracted – do not, have not
Contracted – don’t, haven’t
Other negators: no, nobody, no one, none, nothing, nowhere, neither, never, neither…nor.
No – a determiner. Used with a singular or plural noun, which has no other determiner (article, poss or dem pronoun)
He’s no teacher. (no pedagogical abilities)
Determiners which do not occur outside negative or interrogative sentences, conditional clauses, time clauses beginning with before – non-assertive (yet, ever, at all, any more, long).
Transferred negation: after verbs like believe, suppose, think in the main clause
I don’t believe you two have met, have you?
Double negation: two negatives neutralize the sentence, making it positive
I couldn’t do nothing.
Sometimes adds emphasis.