J, or j, is the tenth letter in the modern English alphabet and the ISO basic Latin alphabet. Its usual name in English is jay (pronounced /ˈdʒeɪ/), with a now-uncommon variant jy /ˈdʒaɪ/.[1][2] When used in the International Phonetic Alphabet for the y sound, it may be called yod or jod (pronounced /ˈjɒd/ or /ˈjoʊd/).[3]
The letter J used to be used as the swash letter I, used for the letter I at the end of Roman numerals when following another I, as in XXIIJ or xxiij instead of XXIII or xxiii for the Roman numeral representing 23. A distinctive usage emerged in Middle High German.[4] Gian Giorgio Trissino (1478–1550) was the first to explicitly distinguish I and J as representing separate sounds, in his Ɛpistola del Trissino de le lettere nuωvamente aggiunte ne la lingua italiana ("Trissino's epistle about the letters recently added in the Italian language") of 1524.[5] Originally, 'I' and 'J' were different shapes for the same letter, both equally representing /i/, /iː/, and /j/; however, Romance languages developed new sounds (from former /j/ and /ɡ/) that came to be represented as 'I' and 'J'; therefore, English J, acquired from the French J, has a sound value quite different from /j/ (which represents the initial sound in the English language word "yet").
In English, ⟨j⟩ most commonly represents the affricate /dʒ/. In Old English, the phoneme /dʒ/ was represented orthographically with ⟨cg⟩ and ⟨cȝ⟩.[7] Under the influence of Old French, which had a similar phoneme deriving from Latin /j/, English scribes began to use ⟨i⟩ (later ⟨j⟩) to represent word-initial /dʒ/ in Old English (for example, iest and, later jest), while using ⟨dg⟩ elsewhere (for example, hedge).[7] Later, many other uses of ⟨i⟩ (later ⟨j⟩) were added in loanwords from French and other languages (e.g. adjoin, junta). The first English language book to make a clear distinction between ⟨i⟩ and ⟨j⟩ was the King James Bible 1st Revision Cambridge 1629 and an English grammar book published in 1633.[8] In loan words such as bijou or Dijon, ⟨j⟩ may represent /ʒ/. In some of these, including raj, Azerbaijan, Taj Mahal, and Beijing, the regular pronunciation /dʒ/ is actually closer to the native pronunciation, making the use of /ʒ/ an instance of hyperforeignism, a type of hypercorrection.[9] Occasionally, ⟨j⟩ represents the original /j/ sound, as in Hallelujah and fjord (see Yodh for details). In words of Spanish origin, where ⟨j⟩ represents the voiceless velar fricative [x] (such as jalapeño), English speakers usually approximate with the voiceless glottal fricative /h/.
In English, ⟨j⟩ is the fourth least frequently used letter in words, being more frequent only than ⟨z⟩, ⟨q⟩, and ⟨x⟩. It is, however, quite common in proper nouns, especially personal names.
The great majority of Germanic languages, such as German, Dutch, Icelandic, Swedish, Danish and Norwegian, use ⟨j⟩ for the palatal approximant /j/, which is usually represented by the letter ⟨y⟩ in English. Notable exceptions are English, Scots and (to a lesser degree) Luxembourgish. ⟨j⟩ also represents /j/ in Albanian, and those Uralic, Slavic and Baltic languages that use the Latin alphabet, such as Hungarian, Finnish, Estonian, Polish, Czech, Serbo-Croatian, Slovak, Slovenian, Latvian and Lithuanian. Some related languages, such as Serbo-Croatian and Macedonian, also adopted ⟨j⟩ into the Cyrillic alphabet for the same purpose. Because of this standard, the lower case letter was chosen to be used in the IPA as the phonetic symbol for the sound.