This thesis investigates syntactic complexity in Russian Sign Language (RSL) and Sign Language of the Netherlands (Nederlandse Gebarentaal, NGT), focusing on two types of complex constructions: complement clauses and relative clauses. A combination of corpus analysis and experimental methods (elicitation and acceptability judgments) is employed to examine these structures in both languages.
The study of complement clauses reveals both cross-linguistic parallels and points of divergence. In both RSL and NGT, complement clauses are distinguished based on word order flexibility: control complements (e.g., complements of try, can, want) permit flexible ordering of the embedded clause, whereas full propositional complements (e.g., complements of think, say, know) obligatorily follow the matrix verb. In RSL, complement clauses are further differentiated by morphosyntactic features, including subject agreement marking on the embedded predicate and the use of an overt complementizer. Both RSL and NGT conform to the Implicational Complementation Hierarchy (Wurmbrand and Lohninger 2023), supporting its applicability across modalities.
Relative clause constructions similarly reveal both shared and language-specific patterns. In both languages, the indexical sign IX can introduce a relative clause, occurring either clause-initially or clause-finally; double exponence of the relative sign is also attested. RSL may additionally employ the relativizer which, which displays a comparable distribution. A notable contrast emerges in the positioning of the head noun: while RSL exhibits a wide range of head positions within the complex construction, NGT shows a strong tendency for the head noun to appear in the first clause, although the exact analysis of NGT relative clauses remains pending.
