the native Berber numeral system, with many using Arabic loans for higher numbers and some from any numeral beyond two. In some Berber languages, the roots for one and two are also borrowed from Arabic. Some South Cushitic numerals are borrowed from Nilotic languages, other Cushitic numerals have been borrowed from Ethiopian Semitic languages. The Cushitic and Chadic numeral systems appear to have originally been base 5. The system in Berber, Egyptian, and Semitic, however, has independent words for the numbers 6-9. Thus, it is possible that the numerals in Egyptian, Berber, and Semitic are more closely related, whereas the Cushitic and Chadic numerals are more closely related to each other. Cognates Afroasiatic languages share a vocabulary of Proto-Afroasiatic origin to varying extents. Writing in 2004, John Huehnergaard notes the great difficulty in establishing cognate sets across the family. Identifying cognates is difficult because the languages in question are often separated by thousands of years of development and many languages within the family have long been in contact with each other, raising the possibility of loanwords. Additionally, because Egyptian is written without vowels before the Coptic period, its use for comparative purposes often relies on vocalic reconstructions that themselves depend on comparisons with other Afroasiatic languages. There are two etymological dictionaries of Afroasiatic, one by Christopher Ehret, and one by Vladimir Orel and Olga Stolbova, both from 1995. Both works provide highly divergent reconstructions and have been heavily criticized by other scholars. Nevertheless, both dictionaries agree on some items and some proposed cognates are uncontroversial. Such cognates tend to rely on relatively simple sound correspondences. Abbreviations: PEC='Proto-Eastern Cushtic', PSC = 'Proto-Southern Cushitic'. See also Afroasiatic phonetic notation Languages of Africa Languages of Asia Proto-Afroasiatic language Nostratic languages Borean languages Notes Citations Works cited General references Bender, Lionel et al. 2003. Selected Comparative-Historical Afro-Asiatic Studies in Memory of Igor M. Diakonoff. LINCOM. Bomhard, Alan R. 1996. Indo-European and the Nostratic Hypothesis. Signum. Diakonoff, Igor M. 1988. Afrasian Languages. Moscow: Nauka. Dimmendaal, Gerrit, and Erhard Voeltz. 2007. "Africa". In Christopher Moseley, ed., Encyclopedia of the world's endangered languages. Ehret, Christopher. 1997. Abstract of "The lessons of deep-time historical-comparative reconstruction in Afroasiatic: reflections on Reconstructing Proto-Afroasiatic: Vowels, Tone, Consonants, and Vocabulary (U.C. Press, 1995)", paper delivered at the Twenty-fifth Annual Meeting of the North American Conference on Afro-Asiatic Linguistics, held in Miami, Florida, on 21–23 March 1997. Finnegan, Ruth H. 1970. "Afro-Asiatic languages