Nikipata njaa jioni, ninakula njugu chache.

Nikipata breaks down like this:

• ni- = I
• -ki- = if/when
• -pata = get, obtain

So nikipata literally means if I get or when I get.

In this sentence, nikipata njaa means if/when I get hungry.

It can mean either if or when, depending on context.

In Swahili, -ki- often introduces a condition or a repeated situation:

• Nikipata njaa, ninakula. = If/When I get hungry, I eat.

Because the main clause is in the present habitual (ninakula), the whole sentence sounds like a general habit:
When/If I get hungry in the evening, I eat a few peanuts.

So here, if and when are both reasonable ways to understand it.

Because each verb in Swahili normally carries its own subject marker.

• ni-ki-pata = I-if/when-get
• ni-na-kula = I-present-eat

So even though both verbs have the same subject (I), each verb still shows that subject.

This is very normal in Swahili.

Because the ni- on the verb already means I.

So:

• Nikipata njaa jioni, ninakula njugu chache. is complete and natural.
• Mimi nikipata njaa jioni, ninakula njugu chache. is possible, but it adds emphasis, like As for me...

In everyday Swahili, subject pronouns such as mimi, wewe, yeye are often omitted unless you want contrast or emphasis.

Ninakula is the present tense, and here it expresses a habitual or general action:

• Nikipata njaa jioni, ninakula njugu chache.
  = When/If I get hungry in the evening, I eat a few peanuts.

This sounds like something the speaker عادة does regularly.

If you wanted a single future situation, you would more likely use nitakula:

• Nikipata njaa jioni, nitakula njugu chache.
  = If I get hungry this evening, I’ll eat a few peanuts.

So ninakula gives a repeated/habitual sense.

Yes, literally it is to get hunger, but that is just how Swahili expresses to get hungry.

So:

• kupata njaa = to get hungry
• nimepata njaa = I’m hungry / I’ve gotten hungry

This is a very natural Swahili expression, even though it sounds more literal in English.

In Swahili, many time words can appear without a preposition.

So jioni by itself can mean:

• in the evening
• this evening
• at evening time

That is completely normal.

Other similar examples:

• asubuhi = in the morning
• usiku = at night
• mchana = during the day

So njaa jioni here means hungry in the evening.

Because in Swahili, descriptive adjectives usually come after the noun.

So:

• njugu chache = a few peanuts
• watoto wadogo = small children
• kitabu kizuri = a good book

Putting chache before njugu would not be the normal basic word order.

Chache means few or a few.

So:

• njugu chache = a few peanuts

It agrees with the noun njugu.

This is useful because English speakers often want to say some peanuts, but chache specifically adds the idea of a small number or small amount.

If the sentence just said ninakula njugu, it would simply mean I eat peanuts or I eat some peanuts, without stressing that it is only a few.

In everyday use, njugu usually refers to peanuts/groundnuts as a food item, often without focusing strongly on singular versus plural the way English does.

Depending on region and context:

• njugu can be translated as peanuts
• it can also be translated as groundnuts

Both are good English equivalents.

In this sentence, njugu chache most naturally means a few peanuts.

Yes. That would also be natural, but it is slightly different in nuance.

• Nikipata njaa jioni... = If/when I get hungry in the evening...
• Nikiwa na njaa jioni... = When I am hungry in the evening...

So:

• kupata njaa focuses on becoming hungry
• kuwa na njaa focuses on being hungry

Both are common, but the original sentence emphasizes the moment hunger comes.

The comma is helpful, but not absolutely required in informal writing.

It marks the break between:

• the condition/time clause: Nikipata njaa jioni
• the main clause: ninakula njugu chache

So the comma makes the sentence easier to read:

• Nikipata njaa jioni, ninakula njugu chache.

That is a good written form.