Based on the patchy distribution of extant cuneiform texts, the SemiticAkkadian language of the native Babylonians was mostly used for economic transactions during the Kassite period, with Sumerian used for monumental inscriptions. Traces of the Kassite language are few:
a Kassite-Babylonian vocabulary with 48 entries, listing bilingual equivalents of god names, common nouns, verbs, and adjective, such as dakaš "star", hašmar "falcon", iašu "country", janzi "king", mašḫu "deity", miriaš "nether world", simbar "young", and šimdi "to give";
the translations of 19 Kassite personal names on the fourth column of a neo-Assyrian era name list, which occasionally contradicts information given in the Kassite-Babylonian vocabulary);
scattered references in Akkadian Lexical lists to Kassite equivalents of divine names, plants, etc, for example the plant names included in the 4-tablet Babylonian Pharmacopoeia, uru.an.na = maštakal, such as ḫašimbur, kuruš, pirizaḫ and šagabigalzu, and terms in the 8-tablet synonym list Malku = šarru, such as allak "rim", and ḫameru "foot";
many proper names in a variety of Akkadian language documents, principally from Babylonia, from Nuzi and from Iran; giving names of deities, people, places and equids;
technical terms relating to animal husbandry, including marks and color designations of horses and asses, found in Akkadian documents, such as those found on a list of Kassite horse names, sambiḫaruk, meaning unknown, and alzibadar, ḫulalam, lagaštakkaš, pirmaḫ, šimriš, and timiraš, color and marking designations of equids; iškamdi, "bit" for a horse; akkandaš, "spoke" of a wheel; kamūsaš and šaḫumaš for bronze parts of a chariot, in contemporary texts;
scattered Kassite words, such as the title bugaš; dardaraḫ, "small metal ornament"; and baziḫarzi, a leather object, in an Akkadian context.
A lack of Kassite texts makes the reconstruction of Kassite grammar impossible at present. Genetic relations of the Kassite language are unclear, although it is generally agreed that it was not Semitic; a relation with Elamite is doubtful. Relationship with or membership in the Hurro-Urartian family has been suggested, based on a number of words. It is not clear whether Kassite would be a distinct language in the Hurro-Urartian phylum, or simply a Southern dialect of Hurrian. If indeed the latter rather than the former, this could surmise that Kassites were merely a tribe of Khurrites that expanded from the north onto the south and settled in Mesopotamia. If Kassite is the former than the latter, this suggests that Hurro-Urartian was an even larger language group and more significant to the region than historical experts have observed and was perhaps spoken by far more many people than previously thought. Morphemes are not known; the wordsburi and burna probably have the same root.
