In East Dangla (Afroasiatic: Chadic, East Branch), there are two complementizers, Pronoun-s, whose pronominal element encodes gender, person, and number of the subject of the main verb, and kàdàr (lexical origin unknown), which are in complementary distribution. Some complement-taking verbs always select the same complementizer; other verbs may occur with either complementizer; still others vary between one complementizer and no complementizer at all. The functions of the two complementizers depend on the main verb whose complements they introduce and whether the subjects of the main and the complement clauses are co-referential. For example, with the verb 'see', the complementizer kàdàr codes INDIRECT evidence, while with the verb 'know', kàdàr codes DIRECT evidence. The functions of a given complementizer can be understood only through an examination of the range of main verbs with which it occurs, the possibility that it or another complementizer (or no complementizer) may occur with a given verb, and the lexical origins of the complementizer, which may in part determine its synchronic distribution.
"Complementation and Modality: Two Complementizers in East Dangla,"
Colorado Research in Linguistics: Vol. 13.
Available at: https://scholar.colorado.edu/cril/vol13/iss1/7