Nganga has research interests in contextual uses of language – an area that fall under postcolonial pragmatics, pragmatics, discourse analysis, sociolinguistics and semantics. From research on language use in the context of the Bukusu funeral funded by the DAAD and BIGSAS he published a book and a number of research articles. From language use among Kenyan female politicians funded by the Heinrich Boell Foundation he published a book chapter.

The research project titled, Language use among the Kenyan urban youth, was funded by the TWAS-DFG. The project is conducted in collaboration with Professor Susanne Muehleisen of Bayreuth University.

Currently I am a member of the research project titled: Invoking the Sacred: The search for Alternative ways of solving climate change induced conflicts. The project is carried out in collaboration with Dr. Joram Tarusarira of Groningen University