Verbal extension

Verbal extension is a Integral part of verbal morphology in most Bantu languages. A suffix, more often than not consisting of VC, is inserted between root and final vowel. It modifies the meaning of the basic verb. More common extensions are applicative, causative, passive, reversive and stative. Others with less predictable surface forms are intensive and positional. Combinations of up to 4 extensions are common. In such a multiple extension, the lexical content correlates with the position of the suffix; more grammatical extensions like passive tend to occur before the final vowel, and more lexical ones in proximity to the root.

Example
from Makua (Bantu P, Mozambique, Oliver Kroeger):

othum-a - to buy otumiha - to sell (with causative -ih) othumiwa - be bought (with passive -iw) otumihiwa - be sold (with causative -ih and passive -iw)

ovar-a - to grasp ovariwa - be snatched (with passive -iw) ovariha - make grasp (with causative -ih) ovarela - catch (with applicative -el) ovareliwa - be caught (with applicative -el and passive -iw)

Link
Utrecht Lexicon of Linguistics