Nominal number in sign languages

This study describes the manifestation of the category of number in sign languages, aiming to identify the values, the main forms and strategies available and some intramodal and intermodal manifestation patterns, considering the noun phrase. To this end, we worked with a sample of 10 sign languages, from different regions and historical groups. Based on secondary data, we identified that some sign languages have optional number marking, which presupposes the presence of the general number, and that other sign languages have obligatory number marking. In sign languages where number marking is optional, the general form is similar to the singular form, expressed by zero. The values of the category of number are singular, plural and dual, expressed by syntactic and morphological strategies, but preference is given for the former. This preference suggests that sign languages are isolating languages with regard to the category of number, differing typologically from spoken languages in this respect. Furthermore, the number system in sign languages appears to be phonologically driven. The supposed trial and quadral values can be expressed by using the iconic plural, in a process of repetition of the singular form in the sign space, with a distinctive and localized pause. Therefore, they were considered to be an instance of direct counting and would be outside the number category. This strategy could create values that go beyond the amount of expected values for the category, in a typological perspective. Also, when mentioned, these values can be substituted for the plural. From the descriptions, morphological strategies suggest an implicational hierarchy, with mouthing being a rarely used strategy and reduplication with displacement being the most prevalent strategy. Another intra-modal feature is the spatial arrangement of the referent, expressed in the category of number.