1. Diphthongs in Classical Arabic and its dialects

In the Semitic linguistic domain a vowel + glide (w or y) compound is called a diphthong. Its Arabic name has the same meaning: ṣawt murakkab ‘compound sound’. The hypothetical Proto-Semitic diphthongs, *aw/*ay, according to the generally accepted view, are conserved in Old Arabic (Cantineau 1960:102), but this conservation is not at all surprising, since Proto-Semitic phonology has been recons…