J (letter) — tenth letter of the English alphabet

Form and typographic notes

Graphically J developed from the Latin letter I. To mark the consonantal use of I, scribes extended the stroke into a tail; over time that tail became the hooked form now recognised as J. The lowercase j retains a tittle in most Latin-based typefaces and handwriting systems. Typographers distinguish several variants of the letter in serif, sans-serif and handwritten styles; cursive forms commonly join the tail to adjacent letters.

History and development

Classical Latin did not distinguish J from I: a single character represented vowel and consonant values. From the late Middle Ages and through the Renaissance writers and printers began to use a tailed form to signal a consonant, and by the 16th century the use of J as separate from I became widespread in European orthographies. The letter ultimately traces its ancestry back through Old Latin and Greek (iota) to a Semitic source.

Pronunciation and use in other languages

In modern English J commonly represents the affricate sound /dʒ/ as in "jump," "jam," and "judge." Other languages assign different values: German and many Slavic languages use J for the palatal approximant /j/ (the sound of English "y" in "yes"); French uses /ʒ/ as in "je"; Spanish uses a guttural fricative (often written with the same letter in older orthographies) and many languages use J in transliteration schemes to represent consonants not written with Latin letters. These differences illustrate how a single graphic sign can carry diverse phonetic meanings.

Uses and symbolic roles

• Common English words beginning with J include jump, journal and justice; many personal names begin with J (e.g., John, James).
• As a symbol, capital J denotes the SI unit joule in science, while in electrical engineering the lowercase j is often used to represent the imaginary unit when i denotes electric current.
• In computing and typography, the letter appears in fonts, encodings and character sets as a basic Latin letter used for identifiers, keywords and text.

For concise alphabetic information see the linked entries on the numeral (10), the concept of a letter, the English language, and the alphabet itself for broader context and further reading.