Watoto wanapaswa kukaa mbali na moto.

Watoto means children. Its singular form is mtoto, meaning child.

This is part of the Swahili noun class system:

• mtoto = one child
• watoto = children

Because watoto is plural, the verb also has to use the plural agreement prefix for that noun class.

Wa- is the subject prefix that agrees with watoto.

Since watoto is a plural noun referring to people, Swahili uses wa- for they.

So:

• watoto = children
• wa- = they

That is why the sentence has wa-napaswa, not a-napaswa or some other prefix.

Wanapaswa means something like:

• they should
• they ought to
• they are supposed to

You can break it down like this:

• wa- = they
• -na- = present tense
• -paswa = be required / be supposed to

So wanapaswa literally carries the idea of they are required/supposed to.

Kukaa is the infinitive form of the verb, meaning to sit, to stay, or to remain, depending on context.

In Swahili, after verbs like wanapaswa (should / are supposed to), the next verb often appears in the infinitive:

• wanapaswa kukaa = they should stay/sit

This is similar to English using to in some structures, although English says should stay rather than should to stay.

It can mean both in different contexts, but here stay is the more natural meaning.

So in this sentence, kukaa mbali na moto means:

• stay away from the fire
• or literally, remain far from the fire

If you translated it as sit far from the fire, that would be understandable, but stay away from the fire is what the sentence really means.

No. In this sentence, na does not mean and.

In the expression mbali na, it means from:

• mbali na moto = far from the fire
• or away from the fire

So mbali na is a very common combination to learn as a unit:

• mbali na = far from / away from

Mbali means far or far away.

Examples:

• mbali = far
• mbali na shule = far from school
• mbali na moto = far from fire

In this sentence, it works together with na to show distance from something.

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

So moto can mean:

• fire
• a fire
• the fire

The exact meaning depends on context.

That is very normal in Swahili. You do not need to add a separate word for the.

The sentence follows a very common Swahili pattern:

Subject + verb + infinitive verb + other information

So here:

• Watoto = subject
• wanapaswa = main verb idea (should / are supposed to)
• kukaa = infinitive verb
• mbali na moto = prepositional/adverbial phrase

So the full structure is:

• Watoto wanapaswa kukaa mbali na moto
• Children should stay away from fire/the fire

This word order is quite straightforward for learners.

You would say:

Mtoto anapaswa kukaa mbali na moto.

Changes:

• watoto → mtoto = children → child
• wanapaswa → anapaswa = they should → he/she should

Here a- is the subject prefix for a singular person in this noun class.

So:

• mtoto anapaswa = the child should

A natural negative version is:

Watoto hawapaswi kukaa karibu na moto.

This means Children should not stay near the fire.

Or, keeping the same idea more directly:

Watoto hawapaswi kukaa karibu na moto is the most natural opposite of the original sentence.

The important verb change is:

• wanapaswa = they should
• hawapaswi = they should not

Notice that in the negative, the verb ends in -i:

• -paswa → -paswi

That is a common pattern in Swahili negative present forms.