Old South Arabian (or Ṣayhadic or Yemenite) is a group of four closely related extinct languages spoken in the far southern portion of the Arabian Peninsula. They were written in the Ancient South Arabian script. There were a number of other Old South Arabian languages (e.g. Awsānian), of which very little evidence has survived, however. A pair of possible surviving Sayhadic languages is attested in the Razihi language and Faifi language spoken in far north-west of Yemen, though these varieties of speech have both Arabic and Sayhadic features, and it is difficult to classify them as either Arabic dialects with a Sayhadic substratum, or Sayhadic languages that have been restructured under pressure of Arabic. Classification issues It was originally thought that all four members of this group were dialects of one Old South Arabian language, but in the mid-twentieth century, linguist A.F.L. Beeston finally proved that they did in fact constitute independent languages. The Old South Arabian languages were originally classified (partly on the basis of geography) as South Semitic, along with Arabic, Modern South Arabian and Ethiopian Semitic; more recently however, a new classification has come in use which places Old South Arabian, along with Arabic, Ugaritic, Aramaic and Canaanite/Hebrew in a Central Semitic group; leaving Modern South Arabian and Ethiopic in a separate group. This new classification is based on Arabic, Old South Arabian and Northwest Semitic (Ugaritic, Aramaic and Canaanite) sharing an innovation in the verbal system, an imperfect taking the form *yVqtVl-u (the other groups have *yVqattVl); Nebes showed that Sabaean at least had the form yVqtVl in the imperfect. Even though it has been now accepted that the four main languages be considered independent, they are clearly closely related linguistically and derive from a common ancestor because they share certain morphological innovations. One of the most important isoglosses retained in all four languages is the suffixed definite article -(h)n. There are however significant differences between the languages. The four main Sayhadic languages were: Sabaean, Minaeic (or Madhabic), Qatabanic, and Hadramitic. Sayhadic had its own writing system, the Ancient South Arabian Monumental Script, or Ms3nd, consisting of 29 graphemes concurrently used for proto-Geʿez in the Kingdom of Dʿmt, ultimately sharing a common origin with the other Semitic abjads, the Proto-Sinaitic alphabet. Inscriptions in another minuscule cursive script written on wooden sticks have also been discovered. The last inscription of these languages dates back to 554 CE,