single    (one) -mwe, umwe, rumwe etc.
(one banana, head of grain, etc.) umuhānyu
(single object) urudēnde
En-En dictionary 
vegetable    (leafy) imboga, irengarenga, ubwākara imbwīja
(assorted raw ~) imboga ziribwa mbisi
(one single vegetable plant) uruboga
En-En dictionary 
grain    impeke, intete, urutete
(a single) agatete
(place for spreading out) imbuga
(storage place) ikigega
(to crush before grinding) kuvūngurīsha
(to form) guhūnda
(to rub to take off chaff) kuvūngura
En-En dictionary 
agatete (udu-)     7  class 7
singular: aka-,aga-
plural: utu-,udu-
  
a single grain
-mwe   adj    1. one, single, 2. some (with pl. prefix), 3. same, (see hamwe, kumwe, kimwe, rimwe, rimwe na rimwe)
uruboga   6  class 6
singular: uru-
  
(no pl.) one vegetable (single plant)
 single found in: Kirundi I (Study lessons)
lesson 113   Reduplicated Verbs
 single found in: Kirundi II (Grammar)
chapter 26   Special Verb Endings