Though estimations vary widely, it is believed by scholars to have been spoken as a single language around 12,000 to 18,000 years ago (12 to 18 kya), that is, between 16,000 and 10,000 BC.
At the same time, scholars disagree as to whether and to what extent the classical Semitic languages of Western Asia are a conservative, faithful representation of PAA morphology.
There is also agreement that a widespread demonstrative pattern of n = masculine and plural, t= feminine goes back to PAA, as well as about the existence of an interrogative pronoun *mV, which may not have distinguished animacy.
Additionally, the importance of verbal gemination and reduplication and the existence of three derivational affixes, especially of a causative -*s-, are commonly reconstructed.
[5] Contrasting proposals of an early emergence, Tom Güldemann has argued that less time may have been required for the divergence than is usually assumed, as it is possible for a language to rapidly restructure due to areal contact, with the evolution of Chadic (and likely also Omotic) serving as pertinent examples.
[9] There are currently not many widely accepted Afroasiatic cognates,[10] and it is difficult to derive sound correspondence rules from a small number of examples.
[1][14] Like cognates, shared morphological features tend to disappear over time, as can be demonstrated within Afroasiatic by comparing Old Egyptian (2600–2000 BCE) with Coptic (after 200 CE).
[18] Current attempts at reconstructing Afroasiatic often rely on comparing individual words or features in the daughter languages, which leads to results that are not convincing to many scholars.
[29] Taking Ehret's labialized velars as equivalent to Orel and Stolbova's non-labialized set, and taking Ehret's extra nasals as equivalent to Orel and Stolbova's
[7] Orin Gensler argues that Rössler's sound change is typologically extremely unlikely, though still possible,[32] while many of the etymologies proposed in support of the theory have been attacked by Gábor Takács.
[30] The most important sound correspondences in the neuere Komparatistik that differ from the traditional understanding are: Attempts to reconstruct the vocalic system of Proto-Afroasiatic vary considerably.
[34] Some of the difficulty in reconstruction is likely related to the use of vowel changes known as apophony (or "ablaut") in the "root-and-pattern" system found in various Afroasiatic languages.
[45] Zygmont Frajzyngier and Erin Shay note that these rules appear to be based on Semitic structures, whereas Chadic includes syllables beginning with vowels as well as initial and final consonant clusters.
[58] Afroasiatic languages feature a "root-and-pattern" (nonconcatenative) system of morphology, in which the root consists of consonants alone and vowels are inserted via apophony according to "templates" to create words.
[55] Carsten Peust likewise supports VSO word order, as this is found in the two oldest attested branches, Egyptian and Semitic.
[68] However, Ronny Meyer and H. Ekkehard Wolff argue that this proposal does not concord with Diakonoff's suggestion that PAA was an ergative-absolutive language, in which subject and object are not valid categories.
[74] Lameen Souag argues that this feminine ending -t is probably a case of a grammaticalized demonstrative, as this feature has also independently developed in some Chadic and Cushitic languages.
[72] In addition to grammatical gender, Igor Diakonoff argues that Afroasiatic languages show traces of a nominal classification system, which was already unproductive in the Proto-Afroasiatic stage.
[84] Several Afroasiatic languages of the Semitic, Chadic, and Cushitic branches attest pluralization via reduplication, a feature which has often been assumed to go back to Proto-Afroasiatic.
[85] Robert Ratcliffe has instead argued that this reduplicating pattern originated after PAA, as a way to allow biradical nouns to insert "internal-a," a process which then became generalized to other roots in some languages; as an alternative hypothesis, they may have developed from forms with plural suffixes.
[95] David Wilson, on the other hand, argues that the case endings are often not cognate in the individual branches of Afroasiatic and that this precludes their reconstruction for the proto-language.
[21][103] Erin Shay argues that *mV- is the only prefix in the AA phylum that clearly goes back to the proto-language rather than possibly being an areal feature.
is also sporadically attested in Semitic and Cushitic, but appears to be absent in Chadic; most modern AA languages use different lexical roots to make the distinction.
[152][153] The prefixes may have originally developed from the pronouns or from auxiliary verbs with pronominal elements, though N. J. C. Kouwenberg argues that the close agreement between the forms in Semitic, Berber, and Cushitic indicates that such grammaticalization must have happened in Proto-Afroasiatic itself or earlier.
[154] Joseph Greenberg proposed that the perfective ("past") stem of PAA had the form *yV-qtVl, based on Semitic, Berber, and Cushitic data.
[161] Maarten Kossmann and Benjamin D. Suchard have reconstructed this verb form as having the role of the imperfective in their hypothetical Proto-Berbero-Semitic while remaining agnostic on its PAA origins.
[173] Maarten Kossmann and Benjamin D. Suchard similarly argue that the vowel patterns of the Semitic and Berber forms cannot be reconciled for their hypothetical "Proto-Berbero-Semitic," indicating that they are not directly cognate.
[144] Carsten Peust, on the other hand, argues that the presence of such verbs in Egyptian, the oldest attested language, and in Chadic and Semitic makes them a good candidate for reconstruction in Proto-Afroasiatic.
[188][189] The *s- and *n-/*m- affixes have been explained as originating in pronominal/deictic expresses or auxiliary verbs which became grammaticalized, a proposal which Andréas Stauder also extends to *-t-.
[199] Aren Wilson-Wright suggests that the root for 'one' has been replaced at least three times throughout the history of Afroasiatic and points to parallels in the Indo-European Greek and Tocharian languages.