Wakiwa wamekula chakula cha jioni, mama na dada yangu walikaa nje kidogo wakisikiliza ngurumo za mbali.

That opening is a dependent clause that sets the scene before the main action.

It tells you the situation before or at the time when the main event happened:

• Wakiwa wamekula chakula cha jioni = after / once they had eaten dinner
• Main clause: mama na dada yangu walikaa nje kidogo... = my mother and sister sat outside for a while...

Swahili often puts this kind of background information first, much like English can do with phrases such as:

• After eating dinner, ...
• Once they had eaten dinner, ...
• Having eaten dinner, ...

So the sentence structure is very natural.

The -ki- marker often shows an action or state happening at the same time as another action, or it can set the background.

Here:

• wakiwa = while being / when they were
• wakisikiliza = while listening

A rough breakdown:

• wa-ki-wa

  • wa- = they
  • -ki- = while / when
  • -wa = be

• wa-ki-sikiliza

  • wa- = they
  • -ki- = while
  • -sikiliza = listen

So -ki- is helping link actions together smoothly without needing extra words like while every time.

Wamekula is the perfect form of kula (to eat), and it means they have eaten or they had eaten, depending on context.

So:

• wakiwa wamekula literally means something like while being in the state of having eaten
• In natural English, that becomes after they had eaten or having eaten

This is a very common Swahili way to express that one action was already completed before the next one.

Breakdown:

• wa- = they
• -me- = perfect/completed action
• -kula = eat

So wamekula = they have eaten / they had eaten

Because the subject is plural: mama na dada yangu = mother and my sister / my mother and sister.

In Swahili, verbs agree with the subject. Since there are two people, the verbs use the plural human subject marker wa-.

You can see it in:

• wakiwa
• wamekula
• walikaa
• wakisikiliza

All of those refer to the same plural subject.

If it were just one person, you would expect a- instead:

• akiwa
• amekula
• alikaa
• akisikiliza

Chakula cha jioni literally means food of evening.

Parts:

• chakula = food, meal
• jioni = evening
• cha = a connector meaning of, agreeing with chakula

So:

• chakula cha jioni = evening meal = dinner

Why cha?
Because chakula belongs to a noun class that uses cha as its associative connector.

You will see the same pattern in other expressions:

• chakula cha mchana = lunch, midday meal
• kikombe cha chai = cup of tea
• kitabu cha mtoto = the child’s book / book of the child

In context, yes, it is very natural to understand this as my mother and sister.

However, strictly speaking, yangu directly attaches only to dada:

• dada yangu = my sister

So the phrase literally looks like:

• mother and my sister

But in real usage, especially with family terms, speakers may omit the possessive on the first noun if the meaning is already obvious.

If you want to make both explicitly possessive, you can say:

• mama yangu na dada yangu

That is the clearest version of my mother and my sister.

It means something like:

• they sat outside for a little while
• they stayed outside for a bit

Breakdown:

• walikaa = they sat / they stayed
• nje = outside
• kidogo = a little, a bit

Here kidogo is being used adverbially, so it does not mean a physically small object. It means for a short time or a bit.

So nje kidogo is best understood as outside for a little while.

It can mean both, depending on context.

Kukaa is a broad verb that can mean:

• to sit
• to stay
• to remain
• sometimes even to live/reside

In this sentence, both sat and stayed are reasonable translations:

• walikaa nje kidogo = they sat outside for a while
• or they stayed outside for a while

English usually forces you to choose one, but Swahili kukaa can cover a wider range.

Wakisikiliza adds a simultaneous action: it tells you what they were doing while they were outside.

So:

• walikaa nje kidogo = they sat/stayed outside for a while
• wakisikiliza ngurumo za mbali = while listening to distant thunder

This is a very common Swahili pattern:

• main action
• plus -ki- form for another action happening at the same time

In natural English, you might translate it as:

• ..., listening to distant thunder
• ..., while listening to distant thunder

Because here ngurumo is being treated as plural: rumbles / peals of thunder.

With this noun, the singular and plural can look the same in form, so the agreement tells you how it is being understood.

• ngurumo ya mbali = a distant rumble
• ngurumo za mbali = distant rumbles

The za agrees with the plural noun class interpretation.

So in this sentence, ngurumo za mbali suggests multiple rumblings or distant thunder sounds, not just one single rumble.

Yes:

• Wakiwa = while they were / being
• wamekula = they had eaten / having eaten
• chakula cha jioni = dinner, evening meal
• mama na dada yangu = mother and my sister / my mother and sister
• walikaa = they sat / stayed
• nje = outside
• kidogo = a little, for a little while
• wakisikiliza = while listening
• ngurumo = rumblings, thunder sounds
• za mbali = distant, from far away

A very literal reading would be:

While being having-eaten the evening meal, mother and my sister stayed outside a little while listening to distant rumblings.

That sounds awkward in English, but it shows how the Swahili pieces fit together. A natural English version would be:

Having eaten dinner, my mother and sister sat outside for a while listening to distant thunder.