Learn Hardcore Swahili: Mwizi mmoja alikamatwa, na sasa anaulizwa maswali na polisi. - One thief was arrested, and now he is being questioned by the police.

alikamata = he/she arrested (someone)
- a- (he/she) + -li- (past) + -kamata (to arrest)
- Example: Polisi alimkamata mwizi. – The police officer arrested the thief.
alikamatwa = he/she was arrested
- a- (he/she) + -li- (past) + -kamat- (root) + -w- (passive) + -a
- The object becomes the subject: Mwizi mmoja alikamatwa. – One thief was arrested.

So alikamata tells you who did the arresting; alikamatwa focuses on the person who was arrested.

Can alikamatwa mean both “was arrested” and “has been arrested”? Which English tense is it?

Yes, alikamatwa can usually be translated as either:

“was arrested” (simple past) or
“has been arrested” (present perfect passive),

depending on context.

Swahili’s -li- past tense does not sharply distinguish between those two English tenses. It generally just says “this happened in the past.” So:

Mwizi mmoja alikamatwa.
- could be “A thief was arrested.” (reported past event)
- or “A thief has been arrested.” (news-style announcement)

Context and surrounding sentences decide which English tense sounds more natural.

In the sentence, na appears twice. Does na always mean “and”? What does it mean in na polisi?

Na has several common meanings: “and,” “with,” “by” (as an agent in a passive sentence).

In your sentence:

..., na sasa ...
- Here na = “and”
- alikamatwa, na sasa... – “was arrested, and now…”
... anaulizwa maswali na polisi.
- Here na introduces the agent in a passive: “by the police”
- literally “is being asked questions by the police.”

So in na polisi it functions like English “by” in a passive construction, not just “and.”

How is anaulizwa formed, and what does it literally mean?

Anaulizwa comes from the verb kuuliza = “to ask.”

Breakdown:

a- = he/she (subject prefix, class 1, singular)
-na- = present tense marker (often “is/are doing”)
-uliz- = root from uliza (ask)
-w- = passive marker (turns “ask” → “be asked”)
-a = final vowel

So anaulizwa literally means “he/she is being asked” (passive).

Together with maswali (questions), you get:

anaulizwa maswali – “he/she is being asked questions” or “he/she is being questioned.”

Why do we say anaulizwa maswali instead of just anaulizwa if “he is being questioned” is already clear?

Swahili commonly uses the pattern:

kuuliza maswali – “to ask questions”
kuulizwa maswali – “to be asked questions”

So maswali is the normal object of kuuliza. Saying only anaulizwa is possible in context, but:

anaulizwa maswali is more explicit and idiomatic, much like English “is being asked questions” rather than just “is being asked.”

You will also hear the more formal/security-style verb:

anahojiwa (from kuhoji – to interrogate), meaning “he/she is being interrogated.”

What tense is anaulizwa? Is it present simple (“is asked”) or present continuous (“is being asked”)?

The -na- tense in Swahili usually matches English present continuous:

anaandika – he/she is writing
anakula – he/she is eating
anaulizwa – he/she is being asked / is being questioned

So in this sentence, anaulizwa is best translated as “is being asked (now)” or “is currently being questioned.”

Why is maswali plural? What is the singular form, and what is the noun class?

Maswali is the plural of swali:

swali = question (singular)
maswali = questions (plural)

This is a typical noun class 5/6 pattern:

singular: often no prefix or other shapes (e.g. swali)
plural: prefix ma- → maswali

Other examples:

jambo → mambo
tunda → matunda

So maswali simply indicates more than one question: “questions.”

Is polisi singular or plural? How does it behave grammatically?

In everyday Swahili:

polisi usually refers to “the police” as a group or institution, like English “police” (which is also a kind of collective noun).
It does not normally change form for plural; the same polisi can refer to one police officer or many, depending on context.
Often, speakers say askari polisi (police officer) for one, and maaskari polisi for more than one.

In the sentence:

na polisi is best read as “by the police” (the police force or police officers in general).

Can I change the word order to anaulizwa na polisi maswali? Is that correct?

Grammatically, anaulizwa na polisi maswali can be understood, but it is not the most natural order.

Typical/most natural order:

anaulizwa maswali na polisi
- [verb passive] + [object: maswali] + [agent: na polisi]

Putting na polisi right after the verb tends to make listeners expect that polisi is the object or part of the main verb phrase, which is less clear.

So it is better to keep:

anaulizwa maswali na polisi – “is being asked questions by the police.”

Is mmoja necessary? Could we just say Mwizi alikamatwa?

You can absolutely say:

Mwizi alikamatwa. – “A thief was arrested.” / “The thief was arrested.”

Mmoja (“one”) adds the idea “one (single) thief”, possibly:

contrasting with “many others,” or
introducing a thief for the first time (a specific but previously unknown individual).

So:

Mwizi mmoja alikamatwa – One thief was arrested.
Mwizi alikamatwa – A/the thief was arrested (number not emphasized).

Both are correct; mmoja is optional and just adds extra information.