adverb

 

used to form a negative phrase after verbs like 'be', 'can', 'have', 'will', 'must', etc, usually used in the short form 'n't' in speech

I won't tell her.

 

used to give the next word or group of words a negative meaning

I told you not to do that.

 

used after verbs like 'be afraid', 'hope', 'suspect', etc in short, negative replies

"Do you think it's going to rain?" "I hope not."