Learn Hardcore Swahili: Jana jioni nilikuwa nikisoma magazeti wakati watoto walikuwa wakicheza uwanjani. - Yesterday evening I was reading newspapers while the children were playing in the field.

nilisoma magazeti = I read the newspapers / I studied the newspapers (simple past, a completed action as a whole).
nilikuwa nikisoma magazeti = I was reading newspapers (past continuous, focusing on the action in progress at that time).

In the sentence Jana jioni nilikuwa nikisoma magazeti wakati watoto walikuwa wakicheza uwanjani, the speaker wants to show that:

both actions (reading and playing) were ongoing at the same time in the past.
the emphasis is on what was happening then, not on the completion of the reading.

What exactly is the structure of nilikuwa nikisoma?

nilikuwa nikisoma is a compound form built from two verbs:

nilikuwa = I was
- ni- = I (1st person singular subject prefix)
- -li- = past tense marker
- -kuwa = verb to be → nilikuwa = I was
nikisoma = I was reading / while I was reading
- ni- = I
- -ki- = progressive / continuous aspect marker (often with a “while/when” feel in past)
- -soma = to read

So nilikuwa nikisoma literally is something like:
I-was I-progressive-read, i.e. I was (in the process of) reading.

Could I say nilisoma magazeti jana jioni instead? What would change?

You can say Nilisoma magazeti jana jioni, but the meaning shifts:

Nilisoma magazeti jana jioni: Yesterday evening I read newspapers.
→ Simple fact, completed activity. No special focus on what else was happening at the same time.
Jana jioni nilikuwa nikisoma magazeti wakati watoto walikuwa wakicheza uwanjani:
→ Emphasizes simultaneity and ongoing action: I was in the middle of reading while the kids were playing.

So nilisoma is fine if you just want to tell what you did; nilikuwa nikisoma is better when you’re setting a scene or contrasting with another action happening at the same time.

What is the role of -ki- in nikisoma and wakicheza?

The -ki- marker shows an ongoing or background action, especially in the past, often with a “while/when (in the middle of doing X)” nuance.

nikisoma: ni- (I) + -ki- (progressive) + soma (read)
→ while I was reading / as I was reading
wakicheza: wa- (they) + -ki- (progressive) + cheza (play)
→ while they were playing / as they were playing

In combination with nilikuwa / walikuwa, it strongly gives the past continuous:

nilikuwa nikisoma – I was reading
walikuwa wakicheza – they were playing

Is walikuwa wakicheza the only way to say “the children were playing”? Could I say watoto walikuwa wanacheza instead?

You can hear both forms, but they are not identical:

watoto walikuwa wakicheza
→ very common, feels a bit more “standard”/neutral; -ki- is the typical progressive, especially in narrative.
watoto walikuwa wanacheza
→ also used, especially in speech; uses -na- (present progressive marker in many contexts) inside a past frame.
In some dialects/registers it can sound slightly more colloquial.

In this kind of narrative sentence, walikuwa wakicheza is usually preferred, because -ki- naturally signals an ongoing background action in the past, matching nilikuwa nikisoma.

What does wakati mean here, and is it closer to “when” or “while”?

wakati literally means time or period, but as a conjunction it usually translates as:

when, while, or as, depending on context.

In wakati watoto walikuwa wakicheza uwanjani:

wakati links the main clause to a simultaneous background event: → when the children were playing in the yard
→ while the children were playing in the yard

Both when and while are acceptable translations. English while captures the idea of two ongoing actions especially well in this sentence.

You can sometimes also see wakati ambapo or wakati huo, which add more emphasis (at that time when…, at that moment when…), but plain wakati works perfectly here.

Why is it uwanjani and not just uwanja? What does the -ni ending do?

The -ni at the end of uwanjani is a locative suffix. It usually means in, at, or on that place.

uwanja = field / yard / pitch / ground
uwanjani = in the yard / on the field / at the ground

So watoto walikuwa wakicheza uwanjani = the children were playing in the yard / on the field.

You could also say:

walikuwa wakicheza katika uwanja – also in the yard, but more explicitly with katika (in).
uwanjani is shorter and very natural in everyday Swahili.

Is magazeti plural? How would I say “a newspaper” instead of “newspapers”?

Yes, magazeti is plural:

gazeti = newspaper (singular, class 5)
magazeti = newspapers (plural, class 6)

To clearly say a (single) newspaper, you can use:

gazeti moja – one newspaper
or simply gazeti, if context already makes it clear it’s one.

So:

Nilikuwa nikisoma gazeti moja – I was reading one newspaper.
Nilikuwa nikisoma magazeti – I was reading newspapers (more than one, or unspecified plural).

Could I move jana jioni to another position in the sentence, like in English?

Yes, word order is quite flexible for time expressions in Swahili. All of these are grammatically fine, with small differences in emphasis:

Jana jioni nilikuwa nikisoma magazeti wakati watoto walikuwa wakicheza uwanjani.
→ Very natural: sets the time first (Yesterday evening…).
Nilikuwa nikisoma magazeti jana jioni wakati watoto walikuwa wakicheza uwanjani.
→ Emphasis slightly more on what you were doing; the time is added after.
Nilikuwa nikisoma magazeti wakati watoto walikuwa wakicheza uwanjani jana jioni.
→ Feels a bit heavier; jana jioni at the end modifies the whole situation.

The most natural for storytelling is the original: Jana jioni … at the beginning, to set the scene.

Why don’t we use an explicit word for “I” (like mimi) in nilikuwa nikisoma?

In Swahili, the subject is usually expressed by a prefix on the verb, not by a separate pronoun:

ni- = I
u- = you (singular)
a- = he/she
tu- = we
m- = you (plural)
wa- = they

So nilikuwa nikisoma already contains I in the ni- prefix. Adding mimi would be for emphasis:

Mimi nilikuwa nikisoma magazeti…
→ I was reading the newspapers (as opposed to someone else).

In neutral sentences, you simply rely on the prefixes and don’t need separate subject pronouns.

Why are both actions expressed in the past continuous? Could I mix simple past and past continuous, like nilikuwa nikisoma and watoto walicheza?

You could mix them, but it would change the nuance:

nilikuwa nikisoma magazeti wakati watoto walicheza uwanjani
→ Feels more like: I was reading newspapers when the children (then) played in the yard – the children’s playing can sound more like a separate, completed event.

Using past continuous for both actions:

nilikuwa nikisoma … watoto walikuwa wakicheza …
makes them clearly simultaneous ongoing actions in the background, like painting a scene.

In storytelling, using past continuous on both sides here feels natural, because you’re describing what everyone was doing at that time, not listing discrete finished events.

Is there a difference between jana jioni and jana usiku? Could I use jana usiku in this sentence?

Yes, there is a time-of-day difference:

jioni = late afternoon / early evening, roughly from around 4–7 pm (varies by region).
usiku = night, after dark, usually later in the evening and nighttime hours.

So:

Jana jioni nilikuwa nikisoma magazeti…
→ Yesterday evening (late afternoon/early evening) I was reading newspapers…

If it actually happened at night, you’d say:

Jana usiku nilikuwa nikisoma magazeti wakati watoto walikuwa wakicheza uwanjani.

That would sound a bit strange in real life (children playing outside at night), but grammatically it’s fine. The choice between jioni and usiku is just about the time of day you want to express.

Could I shorten the sentence by dropping one of the kuwa + -ki- constructions, like Jana jioni nilikuwa nikisoma magazeti wakati watoto walicheza uwanjani?

Grammatically, that sentence is possible, but it subtly changes the feel:

watoto walicheza uwanjani = the children played in the yard (simple past).

So:

Jana jioni nilikuwa nikisoma magazeti wakati watoto walicheza uwanjani.

can be understood as: Yesterday evening I was reading newspapers when the children (then) played in the yard. It doesn’t highlight their playing as an ongoing background action as strongly.

The original:

… wakati watoto walikuwa wakicheza uwanjani.

keeps both actions aligned as ongoing at the same time, giving a smoother, more descriptive scene. That’s why the double kuwa + -ki- structure is popular in narrative sentences like this.