Wasiponunua shampuu leo, watoto wataosha nywele kesho asubuhi.

A helpful way to see it is:

• wa- = they
• -sipo- = a negative conditional pattern meaning if ... not
• -nunua = buy

So wasiponunua means if they do not buy.

Many learners simply memorize wa + sipo + verb as if they don't ... for the they form.

They are both negative, but they do different jobs.

• wasiponunua = if they do not buy
• hawanunui = they do not buy / they are not buying

So wasiponunua introduces a condition, while hawanunui is a normal main-clause negative statement.

It breaks down like this:

• wa- = they
• -ta- = future marker, will
• -osha = wash

So wataosha means they will wash.

The dictionary form is kuosha = to wash, but when the verb is conjugated, the infinitive prefix ku- drops off.

Because wa- is the subject marker for they, especially for plural people nouns.

In this sentence:

• wa-sipo-nunua = if they do not buy
• wa-ta-osha = they will wash

This matches watoto, which means children. In Swahili, verbs agree with the subject, so the wa- tells you the subject is plural people.

Yes — the subject is already inside the verb.

Swahili verbs usually show the subject clearly, so a full noun is often omitted if it is understood.
That means wasiponunua already tells you they do not buy / if they do not buy.

The noun watoto is then stated in the second clause for clarity. This is very normal in Swahili.

Usually, in a sentence like this, most readers will understand it that way from context. But grammatically, wa- by itself just means they.

So:

• it can refer to watoto if that is the intended subject
• but in a wider conversation, it could also refer to some other group already mentioned

Context decides.

In Swahili, nywele is the normal word used for hair, even when English treats hair like a singular mass noun.

So:

• kuosha nywele = to wash hair
• literally, it may feel a bit like wash hairs to an English speaker, but that is just how Swahili expresses it

This is completely natural Swahili.

Because Swahili often leaves possession unstated when it is obvious from the context.

So watoto wataosha nywele naturally means the children will wash their hair here.

If you wanted to make it explicit, you could say:

• watoto wataosha nywele zao = the children will wash their hair

But in many situations, nywele by itself is enough.

It literally means:

• kesho = tomorrow
• asubuhi = morning

Together, kesho asubuhi means tomorrow morning.

That order is very natural in Swahili. English speakers may expect several possible orders, but kesho asubuhi is a standard, common way to say it.

It is a borrowed word, adapted from English shampoo.

Swahili uses many loanwords, especially for modern items and products. The spelling shampuu fits Swahili sound patterns better than the original English spelling.

A learner should also notice that Swahili pronunciation is usually more regular than English, so the vowels are pronounced more clearly.

The singular is mtoto = child.

So:

• mtoto = child
• watoto = children

Because watoto is plural and refers to people, the verb uses the plural people agreement marker wa-.