Nun ن

Nun is the twenty-fifth letter of the modern Arabic order and the fourteenth of the older abjad order, from which it takes the numeral value fifty. Standing alone or at the end of a word it is a deep rounded bowl dropping below the line with a single dot above it. At the beginning and in the middle of a word the bowl vanishes and the letter becomes a short tooth carrying its dot, which is exactly what ba, ta, tha and ya become as well. Five letters share that medial shape and are distinguished only by how many dots they carry and whether the dots are above or below.

Nun is a sun letter, so the lam of the definite article assimilates to it. Its sound is the alveolar nasal, the n of English.

Its name descends from the Northwest Semitic nun, the cognate of Hebrew nun and Syriac nun, whose sense was fish, and it holds the numeral value fifty that Hebrew nun holds.

No letter carries more weight in the rules of recitation. A nun without a vowel, and the nunation that marks indefiniteness at the end of a noun, behave differently according to the letter that follows, and the four ways they can behave are among the first things a student of tajwid learns by name. Nun is also one of the fourteen letters that stand disjoined at the head of a sura, where it opens one of them alone.

Written Arabic records the consonants and leaves much of the pronunciation to be supplied. Nowhere is the gap between the page and the voice wider than with an unvowelled nun, and the rules that close it form the best known chapter of tajwid, the discipline that governs Quranic recitation.

The situation arises in two places: a nun that carries no vowel in the middle or at the end of a word, and the nunation that marks an indefinite noun, written as a doubled vowel sign and pronounced with an n. In both cases what happens next depends entirely on the letter that follows, and the tradition sorts the alphabet into four groups accordingly. Before the letters of the throat the nun is pronounced plainly. Before six particular letters it merges into the following consonant, in some cases with a nasal resonance held and in others without. Before one letter it converts to an m. Before the remaining fifteen it is neither fully sounded nor fully merged but held as a nasal hum for a measured duration.

Each of these has a name, and the naming is the point: the rules are transmitted as a taught body with fixed terminology, learned by ear from a teacher whose own licence names the chain of reciters behind them. A reader can memorise the categories from a book, but the length of a hum and the exact quality of a merged consonant are not things a book conveys.

The atlas records that this system exists, what it governs and how it is transmitted. It does not set out the rules as instruction, because recitation is taught in a living tradition under supervision, and a reference work that offered a substitute for that would be misrepresenting how the knowledge is actually held.