Children's book from 1743, showing I and J considered to be the same letter
The letterJ used to be used as theswash letterI, used for the letter I at the end ofRoman numerals when following another I, as in XXIIJ or xxiij instead of XXIII or xxiii for the Roman numeral twenty-three. A distinctive usage emerged inMiddle High German.[5]Gian Giorgio Trissino (1478–1550) was the first to explicitly distinguish I and J as representing separate sounds, in hisƐpistola del Trissino de le lettere nuωvamente aggiunte ne la lingua italiana ("Trissino'sepistle about the letters recently added in theItalian language") of 1524.[6] 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 theFrench 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 theaffricate/dʒ/. InOld English,/dʒ/ was represented orthographically with⟨cᵹ⟩[7] (equivalent to⟨cg⟩, as⟨ᵹ⟩ in Old English was simply the regular form of the letter G, calledInsular G). Middle English scribes began to use⟨i⟩ (later⟨j⟩) to represent word-initial/dʒ/ under the influence ofOld French, which had a similarly pronounced phoneme deriving from Latin/j/ (for example,iest and laterjest), while the same sound in other positions could be spelled as⟨dg⟩ (for example,hedge).[7] The firstEnglish language books to make a clear distinction in writing between⟨i⟩ and⟨j⟩ were theKing James Bible 1st Revision Cambridge 1629 and an English grammar book published in 1633.[8]
Later, many other uses of⟨i⟩ (later⟨j⟩) were added inloanwords from French and other languages (e.g.adjoin,junta). In loanwords such asbijou orDijon,⟨j⟩ may represent/ʒ/, as in modern French. In some loanwords, includingraj,Azerbaijan andBeijing, the regular pronunciation/dʒ/ is actually closer to the native pronunciation, making the use of/ʒ/ an instance ofhyperforeignism, a type ofhypercorrection.[9] Occasionally,⟨j⟩ represents its original/j/ sound, as inHallelujah andfjord. In words of Spanish origin, such asjalapeño, English speakers usually pronounce⟨j⟩ as thevoiceless glottal fricative/h/, an approximation of the Spanish pronunciation of⟨j⟩ (usually transcribed as avoiceless velar fricative[x], although somevarieties of Spanish use glottal[h]).
In theRomance languages,⟨j⟩ has generally developed from its original palatal approximant value inLatin to some kind offricative. InFrench,Portuguese,Catalan (exceptValencian), andRomanian it has been fronted to thepostalveolar fricative/ʒ/ (like⟨s⟩ in Englishmeasure). In Valencian andOccitan, it has the same sound as in English,/dʒ/. InSpanish, by contrast, it has been bothdevoiced and backed from an earlier/ʝ/ to a present-day/x/ or/h/,[10] with the actual phonetic realization depending on the speaker's dialect.
⟨j⟩ is not commonly used in modern standardItalian spelling. Only proper nouns (such asJesi andLetojanni),Latin words (Juventus), or words borrowed from foreign languages have⟨j⟩. The proper nouns and Latin words are pronounced with thepalatal approximant/j/, while words borrowed from foreign languages tend to follow that language's pronunciation of⟨j⟩. Until the 19th century,⟨j⟩ was used instead of non-syllabic⟨i⟩ in word-initial and intervocalic positions (as inSavoja) and as a replacement for final-ii; this rule was quite strict in official writing.⟨j⟩ is also used to render/j/ in dialectal spelling,e.g.Romanesco dialect⟨ajo⟩[ˈajjo]] (garlic;cf. Italianaglio[ˈaʎʎo]). The Italian novelistLuigi Pirandello used⟨j⟩ in vowel groups in his works written in Italian; he also wrote in his nativeSicilian language, which still uses the letter⟨j⟩ to represent/j/ (and sometimes also [dʒ] or [gj], depending on its environment).[11]
TheMaltese language, though aSemitic language, has been deeply influenced by the Romance languages (especially Sicilian), and also uses⟨j⟩ for/j/.
InBasque, thediaphoneme represented by⟨j⟩ has a variety of realizations according to the regional dialect:[j,ʝ,ɟ,ʒ,ʃ,x] (the last one is typical ofGipuzkoa).
TheRoyal Thai General System of Transcription does not use the letter⟨j⟩, although it is used in some proper names and non-standard transcriptions to represent eitherจ[tɕ] orช[tɕʰ] (the latter followingPali/Sanskrit root equivalents).
In romanizedPashto,⟨j⟩ represents ځ, pronounced[dz].
Following Spanish usage,⟨j⟩ represents[x] or similar sounds in many Latin-alphabet-based writing systems forindigenous languages of the Americas, such as[χ] inMayan languages (ALMG alphabet) and a glottal fricative [h] in some spelling systems used forAymara.
In some areas ofphysics,electrical engineering and related fields,j is the symbol for theimaginary unit (the square root of −1) (in other fields, the letteri is used, but this would be ambiguous as it is also the symbol forcurrent).
In Unicode, a duplicate of 'J' for use as a special phonetic character in historicalGreek linguistics is encoded in the Greek script block asU+03F3ϳGREEK LETTER YOT. It is used to denote thepalatal glide/j/ in the context of Greek script. It is called "Yot" in the Unicode standard, after the German name of the letter J.[16][17] An uppercase version of this letter was added to the Unicode Standard at U+037F with the release of version 7.0 in June 2014.[18][19]
In theWingdings font byMicrosoft, the letter "J" was rendered as asmiley face, sometimes creating confusion in emails after formatting is removed and a smiley turned back into an out-of-context "J".[20]
