Despite the some similarities, there are significant linguistic differences between the Zaza and Gurani languages. Due to these differences, there is no generally accepted view that the Zaza and Gurani languages together form a Zaza-Gorani group on their own in contrast to other Northwestern language groups. The significant linguistic differences between the Zaza and Gorani languages were first noted by
Karl Hadank, the first linguist to linguistically study and analyze the Zaza language. Hadank, in the
Zâzâ und Gûrânî section of his prominent work,
Mundarten der Zâzâ, demonstrated significant linguistic differences between Zaza and Gorani, including important phonological differences, differences and deviations in tense structures, conjugation systems and verbal particles and in glossaries and gender, the very clear gender declension in Zaza, including verb conjugations in contrast to the almost complete absence of gender in Gurani, in prefixs and suffixs, the absence of determinative suffixes in Zaza in contrast to Gorani's explicit use of them, Gorani's characteristic prepositions that Zazaca does not possess. Linguistic features that are assumed to unite Zaza and Gorani are also found in languages and dialects such as
Semnani,
Tati,
Balochi,
Talysh and
Gilaki. Zaza, shows obvious parallels to
Caspian languages (Iranian languages of the Caspian region) that Gurani lacks. Therefore, it has been noted multiple times that there is quite insufficient evidence to substantiate the Zaza-Gorani subgroup, as is often assumed, existing similarities do not imply that Zaza and Gorani ever formed a historical unit and no unifying characteristics have been found from Zaza and the Gorani group to demonstrate that they constitute a group on their own in contrast to other Northwestern language groups. ==Sources==