In English, the name of the letter is the "long U" sound, pronounced /ˈjuː/. In most other languages, its name matches the letter's pronunciation in open syllables.
Pronunciation of the name of the letter ⟨u⟩ in European languages
U derives from the Semitic waw, as does F, and later, Y, W, and V. Its oldest ancestor goes back to Egyptian hieroglyphs, and is probably from a hieroglyph of a mace or fowl, representing the sound [v] or the sound [w]. This was borrowed to Phoenician, where it represented the sound [w], and seldom the vowel [u].
InGreek, two letters were adapted from the Phoenician waw. The letter was adapted, but split in two, with Digamma or wau ⟨Ϝ⟩ being adapted to represent [w], and the second one being Upsilon⟨Υ⟩, which was originally adapted to represent [u], later fronted, becoming [y].
InLatin, a stemless variant shape of the upsilon was borrowed in early times as U, taking the form of modern-day V – either directly from the Western Greek alphabet or from the Etruscan alphabet as an intermediary – to represent the same /u/ sound, as well as the consonantal /w/, num – originally spelled NVM – was pronounced /num/ and via was pronounced [ˈwia].[clarification needed] From the 1st century AD on, depending on Vulgar Latin dialect, consonantal /w/ developed into /β/ (kept in Spanish), then later to /v/.
During the late Middle Ages, two minuscule forms developed, which were both used for /v/ or the vowel /u/. The pointed form ⟨v⟩ was written at the beginning of a word, while a rounded form ⟨u⟩ was used in the middle or end, regardless of sound. So whereas 'valour' and 'excuse' appeared as in modern printing, 'have' and 'upon' were printed 'haue' and 'vpon', respectively. The first recorded use of ⟨u⟩ and ⟨v⟩ as distinct letters is in a Gothic alphabet from 1386, where ⟨v⟩ preceded ⟨u⟩. Printers eschewed capital ⟨U⟩ in favor of ⟨V⟩ into the 17th century and the distinction between the two letters was not fully accepted by the French Academy until 1762.[4][5][better source needed] The rounded variant became the modern-day version of U and its former pointed form became V.
InEnglish, the letter ⟨u⟩ has four main pronunciations. There are "long" and "short" pronunciations. Short ⟨u⟩, found originally in closed syllables, most commonly represents /ʌ/ (as in 'duck'), though it retains its old pronunciation /ʊ/ after labial consonants in some words (as in 'put') and occasionally elsewhere (as in 'sugar'). Long ⟨u⟩, found originally in words of French origin (the descendant of Old English long ⟨u⟩ was respelled as ⟨ou⟩), most commonly represents /juː/ (as in 'mule'), reducing to /uː/ after ⟨r⟩ (as in 'rule'), ⟨j⟩ (as in 'June') and sometimes (or optionally) after ⟨l⟩ (as in 'lute'), and after additional consonants in American English (ado–dew merger). (After ⟨s⟩, /sjuː,zjuː/ have assimilated to /ʃuː,ʒuː/ in some words.)[clarification needed]
The letter ⟨u⟩ is used in the digraphs ⟨au⟩/ɔː/, ⟨ou⟩ (various pronunciations, but usually /aʊ/), and with the value of long ⟨u⟩in⟨eu⟩, ⟨ue⟩, and in a few words ⟨ui⟩ (as in 'fruit'). It often has the sound /w/ before a vowel in the sequences ⟨qu⟩ (as in 'quick'), ⟨gu⟩ (as in 'anguish'), and ⟨su⟩ (as in 'suave'), though it is silent in final ⟨que⟩ (as in 'unique') and in many words with ⟨gu⟩ (as in 'guard').
Additionally, the letter ⟨u⟩ is used in text messaging, the Internet, and other written slang to denote 'you', by virtue of both being pronounced /juː/.
Certain varieties of the English language (i.e. British English, Canadian English, etc.) use the letter U in words such as colour, labour, valour, etc. In American English, the letter is not used, and the words mentioned are spelled as color and so on.
It is the thirteenth most frequently used letter in the English language,[when?] with a frequency of about 2.8% in words.[citation needed]
U is also the source of the mathematical symbol ∪, representing a union. It is used mainly for Venn diagrams and geometry.
It is used for micro- in metric measurements as a replacement for the Greek letter μ (mu), of which it is a graphic approximation when that Greek letter is not available, as in "um" for μm (micrometer).
Media related to U at Wikimedia Commons
The dictionary definition of U at Wiktionary
