gnu / knew / new / nu are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
gnu: (noun) large African antelope having a head with horns like an ox and a long tufted tail.
knew: (verb) be cognizant or aware of a fact or a specific piece of information; possess knowledge or information about. (verb) know how to do or perform something. (verb) be aware of the truth of something; have a belief or faith in something; regard as true beyond any doubt. (verb) be familiar or acquainted with a person or an object. (verb) have firsthand knowledge of states, situations, emotions, or sensations. (verb) have fixed in the mind. (verb) know the nature or character of. (verb) be able to distinguish, recognize as being different. (verb) perceive as familiar.
new: (adjective) not of long duration; having just (or relatively recently) come into being or been made or acquired or discovered. (adjective) having no previous example or precedent or parallel. (adjective) other than the former one(s); different. (adjective) unaffected by use or exposure. (adjective) in use after medieval times. (adjective) (of crops) harvested at an early stage of development; before complete maturity. (adjective) unfamiliar.
nu: (noun) the 13th letter of the Greek alphabet.
gnu: n·UW
knew: n·UW
new: n·UW
nu: n·UW
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)