Mlalamikaji ataapa kesho.

Because Swahili packs subject and tense into the verb itself:

• a- = he/she or class 1 singular
• -ta- = future
• -apa = verb stem from kuapa = to swear / take an oath

So a-ta-apa becomes ataapa: he/she will swear.

Mlalamikaji is a singular noun referring to a person, so it takes class 1 agreement in Swahili. Class 1 singular subjects use the verb prefix a-.

That is why you get:

• Mlalamikaji ataapa = The complainant will swear

If it were plural, the agreement would change:

• Walalamikaji wataapa = The complainants will swear

Mlalamikaji is treated as a class 1/2 noun because it refers to a person.

• singular: mlalamikaji
• plural: walalamikaji

This affects agreement on verbs:

• Mlalamikaji ataapa
• Walalamikaji wataapa

For a learner, the important point is: when the noun is a person, Swahili often uses a- in the singular and wa- in the plural for agreement.

It comes from the idea of complaining.

A useful breakdown is:

• -lalamika = complain
• m- ... -ji = a common way to form a noun meaning person who does X

So mlalamikaji means something like one who complains, which in context can be complainant or plaintiff.

You do not always need to analyze every noun this way when speaking, but it can help you remember vocabulary.

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

So:

• Mlalamikaji can mean a complainant, the complainant, or just complainant
• the exact interpretation comes from context

This is very normal in Swahili. You should not expect a separate word matching English the.

In this kind of sentence, kuapa usually means to swear an oath or to take an oath.

That is especially likely with a word like mlalamikaji, which sounds legal or formal. So the sentence is probably about someone formally swearing, not about using rude language.

As in many languages, context matters.

It looks unusual at first, but it is just the normal combination of parts:

• a- = subject marker
• -ta- = future marker
• -apa = verb stem

So:

• a + ta + apa → ataapa

Nothing strange is happening semantically; it is just how the pieces come together in spelling.

Yes. Kesho means tomorrow, and Swahili word order is somewhat flexible.

Your sentence:

• Mlalamikaji ataapa kesho.

You could also say:

• Kesho mlalamikaji ataapa.

Both are natural. Putting kesho first gives it a bit more emphasis, like Tomorrow, the complainant will swear.

A simple learner-friendly pronunciation guide is:

• Mlalamikaji ≈ m-la-la-mi-KA-ji
• ataapa ≈ a-ta-A-pa
• kesho ≈ KE-sho

A few helpful notes:

• ml- at the start of mlalamikaji can feel difficult for English speakers. Try saying a very short m sound before la: m-la...
• Swahili stress is usually on the next-to-last syllable
• vowels are usually pronounced clearly, not reduced like in English

Yes, if the subject is already understood from context.

Since ataapa already contains the subject marker a-, Swahili can often omit the separate noun:

• Ataapa kesho. = He/She will swear tomorrow.

Adding mlalamikaji makes the subject explicit:

• Mlalamikaji ataapa kesho.

So the noun is not always required, but it is used when you want to identify exactly who is meant.