not
adv. sent.adv. used to make a word or sentence negative. You use it to say that something is not true or does not happen.
adv. used to express negation, denial, or refusal. Functions as a particle to modify a verb, adjective, or another adverb.
I do not like cold weather.
The manager decided not to hire any more staff until the company's profits improved next quarter.
Whether or not the policy succeeds depends less on the initial investment and more on the long-term commitment of the local community leaders.
From Middle English not, nat, variant of noght, naht (“not, nothing”), from Old English *nōht, nāht (“nought, nothing”), short for nōwiht, nāwiht (“nothing”, literally “not anything”), corresponding to ne (“not”) + ōwiht, āwiht (“anything”), corresponding to ā (“ever, always”) + wiht (“thing, creature”). Cognate with Scots nat, naucht (“not”), Saterland Frisian nit (“not”), West Frisian net (“not”), Dutch niet (“not”), German nicht (“not”). Compare nought, naught and aught. More at no, wight, whit.
Typically follows an auxiliary verb or 'be'; when modifying an adjective or noun phrase, it precedes the element it negates.
I not like coffeeI do not like coffeeIn English, 'not' requires an auxiliary verb like 'do', 'have', or 'be' to negate a main verb.