A Swahili passive may name its agent in a phrase beginning with na: Ripoti iliandikwa na Amina “The report was written by Amina.” The phrase is optional because the passive is designed to make the affected participant the grammatical subject and place the doer in the background.
The same word na also means “and” or “with.” Context normally resolves the meaning, but a passive clause containing both an agent and an instrument can become genuinely ambiguous. In those contexts, an active clause or a fuller instrumental phrase is clearer.
From active subject to optional na-phrase
Start with underived andika “write.”
| Clause | Build | Status of Amina |
|---|---|---|
| Amina aliandika ripoti. | a-li-andik-a | subject and agent |
| Ripoti iliandikwa na Amina. | i-li-andik-w-a na Amina | optional oblique agent |
| Ripoti iliandikwa. | i-li-andik-w-a | agent omitted |
Amina aliandika ripoti baada ya kukagua takwimu zote.
Amina wrote the report after checking all the figures.
Ripoti iliandikwa na Amina baada ya takwimu zote kukaguliwa.
The report was written by Amina after all the figures were checked.
Active Amina controls human subject marker a-. Passive class 9 ripoti controls i-; Amina in the na-phrase does not control the verb. This is a change in grammatical relations, not merely a change in word order.
Leaving the agent unexpressed
Agentless passives are natural when the doer is unknown, obvious, unimportant, deliberately backgrounded, or recoverable from context. Swahili does not require a dummy equivalent of English “someone” or “they.”
Simu yangu iliibiwa ndani ya basi jana jioni.
My phone was stolen on the bus yesterday evening.
The speaker probably does not know who stole it. Adding an invented agent would change the information, not complete the grammar.
Matokeo yatatangazwa saa nne kamili asubuhi.
The results will be announced at exactly ten in the morning.
In an institutional context, the responsible body is obvious or deliberately backgrounded. This agentless passive is especially common in (formal) notices, reports, procedures, and news writing, but it is also ordinary in (informal) conversation.
Samahani, kiti hiki tayari kimechukuliwa.
Sorry, this seat has already been taken.
Here naming the person is irrelevant. The passive creates a polite state-of-affairs presentation without accusing anyone.
Naming the agent with na
Use na + noun phrase when the affected subject remains the discourse center but the identity of the doer is still useful.
| Passive build | Promoted subject | Possible na-phrase |
|---|---|---|
| i-li-andik-w-a | ripoti | na Amina |
| wa-li-chunguz-w-a | wagonjwa | na daktari |
| u-li-pand-w-a | mti | na babu yangu |
| zi-me-pit-ish-w-a | kanuni | na bodi |
| li-li-vunj-w-a | dirisha | na jiwe |
| wa-li-andik-ish-w-a | watoto | na wazazi wao |
Wagonjwa walichunguzwa na daktari wa zamu kabla ya saa sita.
The patients were examined by the doctor on duty before noon.
The build wa-li-chunguz-w-a agrees with class 2 wagonjwa. Singular daktari follows na and has no effect on wa-.
Mti huo ulipandwa na babu yangu miaka thelathini iliyopita.
That tree was planted by my grandfather thirty years ago.
The promoted class 3 noun mti controls u- in u-li-pand-w-a. The passive keeps the tree as topic while identifying the planter.
An agent may be a group, institution, or natural force if it is construed as initiating the event.
Kanuni mpya zimepitishwa na bodi baada ya majadiliano marefu.
The new rules have been approved by the board after lengthy discussions.
This is neutral (formal) administrative prose. An active version, Bodi imepitisha kanuni mpya, foregrounds the board and sounds more direct.
Why na can mean either “by” or “with”
Outside passive clauses, na commonly coordinates nouns or introduces accompaniment and instruments. In a passive, semantic plausibility often distinguishes agent from instrument:
| Phrase | Likely role | Reason |
|---|---|---|
| na seremala, by the carpenter | agent | a carpenter can intentionally make something |
| na msumeno, with a saw | instrument | a saw is normally manipulated by an agent |
| na upepo, by/with the wind | cause or force | the force can bring about the event without intention |
Ubao ulikatwa na seremala kwa kutumia msumeno mpya.
The board was cut by the carpenter using a new saw.
This version makes the roles explicit: na seremala names the agent, while kwa kutumia msumeno mpya “using a new saw” names the instrument. The shorter Ubao ulikatwa na seremala na msumeno mpya risks a coordination reading, as though “the carpenter and the saw” formed one phrase.
Dirisha lilivunjwa na jiwe lililorushwa kutoka nje.
The window was broken by a stone thrown from outside.
The stone is an immediate instrument or cause, while the thrower remains implicit. Passive na does not itself encode intention, control, or animacy; the noun and wider situation supply that interpretation.
When active voice is clearer
English formal style often favors passives, but Swahili does not require copying that preference. Use active voice when responsibility, agency, or the sequence of several actors is the main point.
Kamati ilikataa ombi kwa sababu nyaraka mbili zilikosekana.
The committee rejected the application because two documents were missing.
The active makes responsibility immediate. Passive Ombi lilikataliwa na kamati is grammatical, but it is less direct if the question is specifically who rejected it.
Mlinzi alimfungulia mgeni lango kwa ufunguo wa akiba.
The guard opened the gate for the visitor with the spare key.
Three participants are involved: guard, visitor, and gate, plus an instrument. An active applicative clause keeps their roles transparent. A dense passive with repeated na phrases would force the listener to reconstruct too much from context.
Active voice is also preferable when two animate participants could plausibly act on each other.
Asha alimhoji Juma kuhusu malipo yaliyochelewa.
Asha questioned Juma about the delayed payment.
Passive Juma alihojiwa na Asha is clear in isolation, but active voice is easier to process when a following sentence switches the two people's roles.
Agents after a stacked passive
The na-phrase works the same way when passive follows another extension.
Watoto waliandikishwa shuleni na wazazi wao wiki iliyopita.
The children were enrolled at school by their parents last week.
Wa-li-andik-ish-w-a contains causative -ish- before passive -w-. The promoted children control wa-; wazazi wao remains an optional na-agent. The extension order is explained under passive stacking.
Register and discourse effect
Agentless passive is frequent in (formal) regulations and reports because it foregrounds processes or results. It can also conceal responsibility, so an active clause may be ethically clearer in public communication. A named na-agent is neutral across (formal) writing and (informal) speech. Dense strings of na-phrases are grammatical only when their roles remain recoverable; good editing rewrites them.
Common Mistakes
Making the na-agent control agreement
❌ Barua aliandikwa na Amina.
Incorrect — class 9 barua is the passive subject and requires i-.
✅ Barua iliandikwa na Amina jana jioni.
The letter was written by Amina yesterday evening.
Using kwa as the ordinary passive-agent marker
❌ Ripoti ilikaguliwa kwa mhasibu.
Incorrect for ‘by the accountant’ — kwa does not introduce the ordinary passive agent here.
✅ Ripoti ilikaguliwa na mhasibu kabla ya kutumwa.
The report was checked by the accountant before being sent.
Assuming the agent must always be stated
⚠️ Mkoba wangu uliibiwa na mtu nisiyemjua.
Grammatical, but unnecessary when the speaker does not know or need to identify the thief — the passive agent can simply be absent.
✅ Mkoba wangu uliibiwa nilipokuwa nikipanda basi.
My bag was stolen while I was boarding the bus.
Creating an ambiguous chain of na-phrases
⚠️ Meza ilitengenezwa na fundi na msumeno huu.
Grammatical but ambiguous — na may coordinate the carpenter and saw or introduce an instrument.
✅ Meza ilitengenezwa na fundi kwa kutumia msumeno huu.
The table was made by the carpenter using this saw.
Key Takeaways
- A passive agent is optional and is introduced by na.
- The promoted subject, not the na-agent, controls subject concord.
- Because na also means “and/with,” use kwa kutumia to make an instrument explicit when necessary.
- Agentless passives foreground events and results; active voice foregrounds responsibility.
- Active clauses are often clearer when several animate participants and instruments occur together.
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Start learning Swahili →Related Topics
- Forming the PassiveB1 — Form Standard Swahili passives with -w-, -iw-, and -ew- while preserving TAM and making the promoted participant control subject agreement.
- Object Promotion in the PassiveB2 — Track how a theme, recipient, or applied object becomes the passive subject and takes over subject concord from the omitted agent.
- Passive after Other ExtensionsC1 — Place passive last after causative, applicative, and reciprocal morphology, then interpret which participant the complete extension stack promotes.
- Personal and Class Subject MarkersA2 — Choose the first marker in a Swahili finite verb from the subject's person, number, or noun class.