# N1 vs not

> English confusable word pair

## The two words

### N1
*noun · frequency rank #30,893*
The rotational speed of the low-pressure spool of a multiple-spool gas turbine engine, expressed as a percentage of a certain reference rotational speed.

### not
*adverb · IPA /nɒt/ · frequency rank #23*
Negates the meaning of the modified verb.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/n1-vs-not