As mentioned briefly in §2.1, spoken languages have different ways to express negation. Across sign languages, negation is expressed very similarly. Most frequently, it is realized by an obligatory head movement (e.g. a headshake), often in combination with a manual negative particle. In spoken languages, negative structures involving two negative elements can be found as well (for example, in French) and this typological pattern has been referred to as ‘split negation’. Therefore, Pfau (2002, 2008) argues for DGS that the language fits well in the suggested typology in that it exhibits split negation, with one element being an (optional) negative particle and the other one a non-manual negative affix.
In addition, Zeshan (2004a, 2006) suggests a sign language specific typology. She proposes that sign language negation comes in two different types: manual dominant and non-manual dominant systems. Jordanian Sign Language (LIU, Hendriks 2007) and Italian Sign Language (LIS, Geraci 2005) have been argued to be of the former type. Manual dominant systems are characterized by the fact that a manual negation sign is obligatory; that is, a sentence cannot be negated by a non-manual marker only, irrespective of its scope, as is illustrated by the LIS example in (12a). Additionally, the non-manual negative marker commonly accompanies the manual marker, but is unlikely to spread beyond this marker across (part of) the clause (12b).
In contrast, in non-manual dominant systems, a manual negative particle is optional, whereas the non-manual negative marker is obligatory and capable of spreading. Besides DGS, NGT, ASL, and Indopakistani Sign Language (IPSL) display negation systems of the non-manual dominant type (Zeshan 2004a, 2006). The NGT example in (13) is representative of a non-manual dominant negative system. Note the lack of a negative particle in this example as well as the spread of the headshake over the verb phrase.