- Not is defined as a word used with a verb to make a negative.
An example of not used as an adverb is in the phrase "not happy," which means unhappy.
Origin of notMiddle English not, unstressed form of noht, nought, naught: see nought
Origin of notMiddle English, alteration of naught, nought; see naught. Usage Note: The positioning of not and other negatives in a sentence is important to avoid ambiguity. The sentence All classes are not open to enrollment could be taken to mean either “All classes are closed to enrollment” or “Not all classes are open to enrollment.” Similarly, the sentence Kim didn't sleep until noon could mean either “Kim went to sleep at noon” or “Kim got up before noon.” • Not only and but also are usually classified as correlative conjunctions. They add emphasis to each part of the construction and suggest that the second part is particularly unexpected or surprising. As with both &ellipsis; and and other correlatives, parallelism requires that each conjunction be followed by a construction of the same grammatical type. Thus, She not only bought a new car but also a new lawnmower displays faulty parallelism, where She bought not only a new car but also a new lawnmower does not, because both not only and but also are followed by noun phrases. See Usage Note at only.
- Negates the meaning of the modified verb.
- Did you take out the trash? No, I did not.
- Not knowing any better, I went ahead.
- To no degree
- That is not red; it's orange.
In modern usage, the form do not ... (don’t ...) is preferred to ... not for all but a short list of verbs (is/am/are/was/were, have/has/had, can/could, shall/should, will/would, may/might, need):
- They do not sow. (modern) vs. They sow not. (KJB)
American usage tends to prefer don’t have or haven’t got to have not or haven’t, except when have is used as an auxiliary (in the idiom have-not):
- I don’t have a clue or I haven’t got a clue. (US)
- I haven’t a clue or I haven't got a clue. (outside US)
- I haven’t been to Spain. (universal)
The verb need is only directly negated when used as an auxiliary, and even this usage is rare in the US.
- You don’t need to trouble yourself. (US)
- You needn’t trouble yourself. (outside US)
- I don’t need any eggs today. (universal)
The verb dare can sometimes be directly negated.
- I daren't do that.
- And not.
- I wanted a plate of shrimp, not a bucket of chicken.
- He painted the car blue and black, not solid purple.
- The construction “A, not B” is synonymous with the constructions “A, and not B”; “not B, but A”; and “not B, but rather A”.
- (slang, 1990s) Used to indicate that the previous phrase was meant sarcastically or ironically.
- I really like hanging out with my little brother watching Barney... not!
- Sure, you're perfect the way you are... not!
- Unary logical function NOT, true if input is false, or a gate implementing that negation function.
- You need a not there to conform with the negative logic of the memory chip.
From Middle English not, nat, variant of noght, naht (“not, nothing”), from Old English *nōht, nāht (“nought, nothing”), short for nōwiht, nāwiht (“nothing”, literally “no thing, no creature”), corresponding to nā (“no”) + 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 and aught. More at no, wight.