convince    kwemeza, gutururuza, guhinyuza
(to be convinced, after proof or persuasion) gushirwa
En-En dictionary 
guhinyuza (-hinyuje)     v    1. to check over a thing, 2. to prove, give proof, 3. to convince, 4. to verify, 5. to condemn, 6. to disgrace, 7. to speak truth, 8. to divine
gushirwa (-shizwe)     v    1. to not quit without accomplishing a certain thing, 2. to be convinced after proof or persuasion, to be satisfied, 3. to be astonished, 4. to be put
gutururuza (-tururuje)     v    1. to push a person down where he belongs, 2. to squelch, 3. to prevent, to stop, 4. to convince, 5. to catch swarming bees
kwemeza (-emeje)     v    1. to convince, 2. to prove, 3. to confirm, 4. to cause to admit or accept