náni 'who'; wápi 'where'; tángo níni 'when'; ndéngé níni 'how' (ndéngé níni also has the noncompound equivalent bóní; both are equally frequent).
Tángo is a noun, meaning 'moment'.
Ndéngé is a noun, meaning 'manner'.
Source: nd
Source: nd
Source: nd
Source: nd