Watoto wanasoma kitabu wakisubiri chakula cha jioni.

Watoto means children. It is the plural of mtoto (child).

This noun belongs to the human noun classes:

• mtoto = one child
• watoto = children

Because watoto is plural and refers to people, other words in the sentence that relate to it also use plural human agreement, such as wa- in wanasoma and wakisubiri.

The wa- is the subject marker that agrees with watoto.

You can break wanasoma down like this:

• wa- = they (for plural people)
• -na- = present tense
• -soma = read / study

So wanasoma means they are reading or they read, depending on context.

Because the subject is watoto, the verb must use wa-.

It can mean both.

Kusoma is a very common verb that may mean:

• to read
• to study
• sometimes more broadly to learn from text/schoolwork

In this sentence, because the object is kitabu (book), the most natural meaning is to read:

• wanasoma kitabu = they are reading a book / the book

If the sentence had no object, the meaning could more easily be studying, depending on context.

Kitabu is singular: book.
Vitabu is plural: books.

So:

• kitabu = book
• vitabu = books

The sentence uses kitabu, which suggests:

• the children are reading one book, possibly together, or
• Swahili is simply leaving the exact English article unspecified

Swahili does not have a/an/the, so kitabu could mean:

• a book
• the book
• sometimes just book, depending on context

Swahili normally does not use articles like English a, an, and the.

So kitabu can mean:

• a book
• the book

And chakula cha jioni can mean:

• dinner
• the evening meal

You figure out which one is intended from context, not from a separate article word.

Wakisubiri means while they are waiting or as they wait.

It is built like this:

• wa- = they
• -ki- = while / when / if (depending on context)
• -subiri = wait

In this sentence, the most natural meaning is while waiting:

• wakisubiri chakula cha jioni = while they are waiting for dinner

So the sentence describes two actions happening at the same time:

1. the children are reading
2. they are waiting for dinner

The -ki- marker often links an action to another action. It can mean things like:

• while
• when
• if

In this sentence, it expresses a simultaneous action:

• wanasoma ... wakisubiri ...
• they are reading ... while waiting ...

So -ki- is very useful for saying that one action happens during another one.

Examples:

• Anatembea akiimba. = He/She walks while singing.
• Watoto wanacheza wakicheka. = The children are playing while laughing.

Because the subject is already built into the verb.

In wakisubiri:

• wa- already means they (for plural people)

So Swahili does not need to say a separate pronoun like English does.

This is very normal in Swahili:

• wanasoma = they are reading
• wakisubiri = while they are waiting

The subject marker inside the verb tells you who is doing the action.

Literally, it means something like food of evening.

Breakdown:

• chakula = food / meal
• cha = of (agreeing with chakula)
• jioni = evening

So:

• chakula cha jioni = evening meal = dinner

This is a very common Swahili way of making noun phrases:

• noun + agreement word + noun

For example:

• chakula cha mchana = lunch, literally food of daytime/noon
• chai ya asubuhi = morning tea/breakfast tea

Because cha has to agree with the noun chakula.

Chakula belongs to the ki-/vi- noun class, and the associative/genitive connector for singular nouns in that class is cha.

So:

• chakula cha jioni = evening meal

If the noun belonged to a different class, the connector would change. For example:

• mtoto wa shule = school child
• kitabu cha mwanafunzi = the student's book
• meza ya mwalimu = the teacher's table

This kind of agreement is a major feature of Swahili grammar.

Yes. It is very natural.

The structure is:

• Watoto = subject
• wanasoma kitabu = main action
• wakisubiri chakula cha jioni = accompanying action

So the sentence is basically:

• Children are reading a book while waiting for dinner.

Swahili often puts the main action first and then adds a -ki- clause to show another action happening at the same time.

Yes, in some contexts it could.

The -na- tense can refer to:

• something happening right now
• a more general present situation

So wanasoma could mean:

• they are reading
• they read
• in some contexts, even they study

But in this sentence, with wakisubiri chakula cha jioni, it strongly sounds like an action happening at that moment:

• the children are reading while they wait for dinner

In general, yes: -ki- can sometimes mean if or when depending on the sentence.

But here, the context makes while waiting the best interpretation.

Compare:

• Wakisoma, wataelewa. = If/when they read, they will understand.
• Wanasoma wakisubiri chakula cha jioni. = They are reading while waiting for dinner.

So the meaning of -ki- depends a lot on context. In this sentence, it clearly describes a simultaneous action, not a condition.