Agentless Passive

The passive extension attaches directly to the verb root. The exact form depends on the verb's ending:

• Consonant-final roots: Insert -w- before the final -a (e.g., piga → pigwa).
• Vowel-final Bantu roots: Verbs ending in -ua, -oa, or -aa drop the final -a and add -liwa or -lewa based on vowel harmony (use -lewa if the preceding vowel is e or o, otherwise use -liwa) (e.g., nunua → nunuliwa, ondoa → ondolewa). For verbs ending in -ia or -ea, some simply insert -w- (e.g., tumia → tumiwa), but many resurrect a historical 'l' and take -liwa or -lewa (e.g., pokea → pokelewa, ingia → ingiliwa). Note the highly common irregular passive form for the verb ua (to kill), which becomes uawa.
• Monosyllabic verbs: Take -iw- or -ew- (e.g., la → liwa; pa → pewa).
• Arabic loans: Verbs ending in -i or -e simply add -wa (e.g., rudi → rudiwa, samehe → samehewa). Those ending in -u replace the final vowel with -iwa (e.g., jibu → jibiwa). Those ending in -au add -liwa (e.g., dharau → dharauliwa), and those ending in -uu replace the final -u with -liwa (e.g., nukuu → nukuliwa).

When forming a passive sentence, the object of the active sentence becomes the new subject. This means the Subject Agreement prefix must change to agree with the new subject's noun class (e.g., Chakula kilipikwa - The food was cooked).

Additionally, Swahili frequently uses passive forms with the Applicative -ia extension. In these cases, the indirect object becomes the subject (e.g., Nilipewa kitabu - I was given a book; Aliandikiwa barua - He/She was written a letter).

The agentless passive is extremely common in everyday Swahili. It is crucial to distinguish it from the Stative -ika extension. The passive implies an external agent caused the event, while the stative describes a resulting state or condition without implying an agent. For example, Kikombe kimevunjwa means 'The cup was broken (by someone)', whereas Kikombe kimevunjika means 'The cup is broken (focus on the state)'.