Learn Hardcore Swahili: Jana mchana, mimi niliona Asha sokoni. - Yesterday afternoon, I saw Asha at the market.

ni- in ni-li-ona is the subject prefix on the verb. Swahili verbs must carry a subject prefix (except in some imperative forms). So the verb needs that ni-.
mimi is the independent pronoun “I / me”. It is optional and is usually added for:
- emphasis: I (as opposed to someone else) saw Asha.
- clarity or focus at the start of a sentence.

So:

Niliona Asha sokoni. = I saw Asha at the market. (normal, correct)
Mimi niliona Asha sokoni. = I saw Asha at the market. (with extra emphasis on I).

Can I drop mimi and just say Jana mchana, niliona Asha sokoni? Is that still correct?

Yes, that is fully correct and very natural.

Jana mchana, niliona Asha sokoni. – completely fine, common, and usually preferred in neutral speech.
Adding mimi just stresses the subject:
- Jana mchana, mimi niliona Asha sokoni (sio mtu mwingine).
  Yesterday afternoon, I saw Asha at the market (not someone else).

What does the -li- in niliona mean?

In ni-li-ona, the verb structure is:

ni- = subject prefix for “I”
-li- = past tense marker (“did, -ed”)
-ona = verb root “see”

So niliona literally breaks down as: ni- (I) + -li- (past) + -ona (see) → I saw / I did see.

Why is it sokoni and not just soko? What does the -ni ending do?

Soko means “market” (the place, as a noun).

-ni is a locative suffix, meaning “at / in / on” depending on context.

soko = market
sokoni = at the market / in the market area

So Asha sokoni is best understood as “Asha (was) at the market.”
The sentence focuses on the location where you saw Asha.

There’s no “was” in Asha sokoni. How do we know it means Asha was at the market?

In Swahili, the copula “to be” is often omitted in the present and in some simple structures.

Asha sokoni can be understood as “Asha is/was at the market” depending on the wider sentence tense.
Since the main verb niliona is in the past, the whole event is understood as past: I saw Asha (who was) at the market yesterday afternoon.

You could also say:

Nilimwona Asha akiwa sokoni. – I saw Asha while she was at the market. (more explicitly “while being at the market”)

But in everyday speech, Asha sokoni after a past verb is enough to imply “she was at the market.”

Why is it Jana mchana and not mchana jana? Is there a rule about time expressions?

Both Jana mchana and mchana jana are possible in some contexts, but Jana mchana is the standard, most natural way to say “yesterday afternoon.”

The usual pattern for combined time phrases is:

[larger time] + [smaller time]

So:

jana mchana = yesterday (larger) + afternoon (smaller)
leo asubuhi = today morning
kesho jioni = tomorrow evening

Mchana jana might appear in speech to add a contrast like “(this) afternoon, yesterday”, but for a learner, stick with jana mchana as the normal form.

Do I need the comma in Jana mchana, mimi niliona Asha sokoni?

The comma is a writing convention, not a spoken feature.

In speech, you simply pause slightly after Jana mchana.
In writing, a comma after the initial time phrase is common but not mandatory.

So all of these are acceptable in meaning:

Jana mchana mimi niliona Asha sokoni.
Jana mchana, mimi niliona Asha sokoni.

The meaning stays the same.

Could I change the word order and say Niliona Asha sokoni jana mchana?

Yes, that is possible and understandable:

Niliona Asha sokoni jana mchana.

Swahili word order is fairly flexible with time and place phrases:

Jana mchana, niliona Asha sokoni.
Niliona Asha jana mchana sokoni.
Niliona Asha sokoni jana mchana.

All can work, but the most natural, neutral version is usually:

Jana mchana niliona Asha sokoni.

Putting the time phrase at the beginning is very common.

What is the infinitive or dictionary form of niliona?

The dictionary (infinitive) form is kuona – to see.

kuona = to see
ni-li-ona = I + past + see → I saw
utaona = u- + -ta- + -ona = you will see

So when you look up verbs, you will find kuona, not niliona.

Is there a way to say “I saw her (Asha) at the market” using an object marker?

Yes. You can add an object marker (OM) into the verb:

Nilimwona Asha sokoni.

Breakdown:

ni- = I (subject)
-li- = past
-m- = object marker for “him/her” (class 1 person)
-wona = (a variation of) -ona “see”

So literally: I-past-her-saw Asha at the market.
In practice, Niliona Asha sokoni and Nilimwona Asha sokoni can both translate to “I saw Asha at the market.” The version with -m- puts a bit more focus on the person as the object.

If the subject is Asha, do I still need a separate word like ye or yeye?

No separate pronoun is needed in normal statements.

Asha alienda sokoni. = Asha went to the market.
- a- = subject for “she/he”
- -li- = past
- -enda = go

You would only add yeye for emphasis or contrast:

Yeye Asha alienda sokoni, si mimi.
It was Asha who went to the market, not me.

In Jana mchana, mimi niliona Asha sokoni, Asha is just a proper noun; she doesn’t need a pronoun because she’s the object, not the subject.

Is mimi always “I”, or can it mean “me” as well?

Mimi covers both “I” (subject) and “me” (object), depending on its position:

Mimi niliona Asha. – I saw Asha.
Asha alinionyesha mimi. – Asha showed me. (literally showed me, me)

Swahili doesn’t distinguish I/me the way English does; mimi is just the independent 1st-person singular pronoun, and its role is clear from context and word order.