Phonetics and phonology
Most Afro-Asiatic languages share a set, or inventory, of particular consonants. One group in this inventory is called the pharyngeal fricatives and is exemplified in Egyptian, Cushitic, Amazigh, and Semitic by ħ and ʿ (“ayn”). A second commonly used group of consonants is an emphatic set, similar to the pharyngeal fricatives but with phonetically quite different articulations; characteristically, emphatics are formed deeper down in the vocal tract and may involve different airstream mechanisms.
Amazigh and Arabic have three major types of consonants: pharyngealized (articulated at the back of the vocal tract with the pharynx), velarized (in which the back of the tongue touches the soft palate), and uvularized (articulated at the back of the vocal tract with the uvula). In South Arabian, Ethio-Semitic, Cushitic, and Chadic languages, there are consonants characterized by the following “manners,” or types of air flow: explosive glottals, which occur when a complete closure is suddenly released; ejective glottals, which involve compressed air moving from the glottis and toward the lips; and implosive glottals, which involve air moving temporarily into the oral cavity before the release of the glottal closure allows the air from the lungs to stream out again. The glottal stop ʾ (“hamzah”) is used as a separate consonant. Whereas the semivowels y (IPA: j) and w tend also to be used as consonants, consonants such as ʾ and *H̥ show functional affinities with vowels.
Reconstructions based on Semitic and Cushitic alone point toward a balanced inventory of three short vowels (*i, *u, and *a) and three long vowels (*ii, *uu, and *aa). This, however, is unlikely to have been the case in the protolanguage; rather, in light of Chadic and Amazigh data and a more abstract level of phonological analysis, a two-vowel system (*a, *ə) appears more likely there.
Some phonemes, such as *y, *w, *ʾ, and *H̥, appear to serve both as consonants (called “weak radicals” when they form part of a root) and as vowels (in which case they become *i, *u, and *a), depending on their distribution in the root or word. Conceivably, Proto-Afro-Asiatic lacked a vowel system in the traditional sense but may have distinguished consonants and sonants instead; examples of sonants would have been, for instance, *m, *n, *r, *l, *y, *w, *ʾ, *H̥, and *H̥w, which could perform the functions of either consonants or vowels. As vowels they gave rise to *i, *u, and *a and sequences such as *am, *an, *ar, *al, *ai, *au, and *ʾa in the languages spoken today.
The majority of Afro-Asiatic languages are tone languages, meaning that in addition to consonants and vowels, the pitch of the voice is used to differentiate between words or smaller meaningful units. The use of tones is attested in Chadic, Cushitic, and Omotic but in neither Semitic nor Amazigh. In some Cushitic and Omotic languages, however, tonality resembles pitch accent, a linguistic feature somewhat comparable to stress in European languages, albeit relying solely on higher pitch for “stressed” syllables rather than automatically combining higher pitch with loudness or duration. Some linguists believe that Proto-Afro-Asiatic was a tone language and that daughter languages such as Semitic, Amazigh, and possibly Egyptian subsequently lost all tonal distinctions. Other authors assume Proto-Afro-Asiatic was a pitch-accent language; these linguists consider it more likely that tonality emerged independently in Chadic, Cushitic, and Omotic, assuming that tonal distinctions, at least in Chadic, developed out of the pitch-accent system of Proto-Afro-Asiatic in conjunction with the pitch-lowering effect of certain syllable-initial consonants called tonal depressors. Such automatic pitch lowering is well attested outside Chadic both within and outside Africa. Thus, long periods of contact with speakers of genuine African tone languages of Niger-Congo and Nilo-Saharan stock may have assisted the historical shift from pitch accent to tone systems in Afro-Asiatic.
Afro-Asiatic languages are characterized by a “root and pattern” system in which the basic meaning of a word is manifested in the consonants alone. The sequence of vowels, which is known as the pattern, adds grammatical information and may modify the basic lexical meaning of the root, sometimes in combination with prefixes or suffixes. The root k-t-b-, which means ‘write’ in Arabic, provides illuminating examples: adding the vowel pattern -a-a-a yields the form kataba ‘he has written,’ while the zero-initial pattern Ø-u(-Ø) plus the prefix ya- and the suffix -u yields ya-ktub-u ‘he is writing.’
|√k-t-b||’write’ (Arabic)||katb-un||’act of writing’|
|katab-a||’he corresponded (with)’||yu-katib-u||’he is in correspondence’|
|ʾa-ktaba||’he has made (somebody) write’||mu-katib-un||’the corresponding one’|
|yu-ktib-u||’he is making (somebody) write’||katib-un, pl. kuttab||’someone writing, scribe’|
|mu-ktib-un||’making (somebody) write’||kitab-un, pl. kutub||’book’|
|ma-ktab-un||’the place to write, school’||ma-ktub-un||’written’|
It is no coincidence that the West Semitic quasi-alphabets, which developed in the 2nd millennium bce and from which all later Afro-Asiatic writing systems derive (including tifinagh of the Amazigh), are made up of signs that represent a consonant followed by any or no vowel, thus reflecting the structural properties of this characteristic root and pattern system.