Ayn ع

Ayn is the eighteenth letter of the modern Arabic order and the sixteenth of the older abjad order, from which it takes the numeral value seventy. It is a moon letter, and it joins on both sides.

No letter of the script changes more with position. Standing alone it is a hook above a deep bowl that curls back below the line. At the end of a word joined to what precedes it, the bowl remains but the hook flattens. In the middle of a word it becomes a small closed triangle on the line, and at the beginning a shallow open hook. A reader who has learned the isolated form alone will not recognise the other three, which is why teaching the Arabic alphabet from a chart of isolated letters gets a learner further with ba than with ayn.

Its sound is a voiced pharyngeal fricative, produced by constricting the throat well below the point at which any European language forms a consonant. Together with its voiceless partner, the pharyngeal ha, and with the glottal stop and the plain glottal h, it belongs to the group the grammatical tradition calls the letters of the throat. The tradition further holds that the hamza sign, which writes the glottal stop, was drawn from the head of ayn, so the two are linked in the shape of the writing as well as in the place of articulation.

Its name descends from the Northwest Semitic ayin, whose sense was eye, and it is the cognate of Hebrew ayin and Syriac e. It is one of the fourteen letters that appear disjoined at the head of a sura.

Arabic phonology is organised in the grammatical tradition by place of articulation, running from the throat outward to the lips, and the classification is old: it is set out in the eighth century, in the work associated with al-Khalil ibn Ahmad and in the account of his pupil Sibawayh, and it is still the framework in which the recitation manuals are written. Six consonants are assigned to the throat: the glottal stop and the plain h at the outermost point, ayn and the pharyngeal ha in the middle, and ghayn and kha at the point nearest the mouth.

The grouping is not merely descriptive. It carries rules. Arabic word roots do not freely combine consonants from the same articulatory group, so a root containing ayn is unlikely also to contain ha, and lexicographers used the constraint to organise dictionaries. In recitation the throat letters govern one of the best known rules of tajwid, under which a nun with no vowel is pronounced clearly rather than assimilated when a throat letter follows it. That rule is taught early and by name.

The same six letters are the ones that European learners find hardest and that European transliteration handles worst. Ayn and the glottal stop are frequently dropped altogether in roman spellings of Arabic names, ghayn becomes gh and kha becomes kh by convention, and the two h sounds are usually written with the same letter. The atlas follows the common convention of transliterating without diacritics, and distinguishes the pairs by name where the distinction matters rather than by marks a reader cannot see.