Mimi ninanunua nguo nzuri sokoni.

Yes. In Swahili, ni- in ninanunua already means I, so mimi is not required.

• Ninanunua nguo nzuri sokoni = I am buying nice clothes at the market
• Mimi ninanunua nguo nzuri sokoni also means the same thing, but mimi adds emphasis.

So mimi is often used for contrast or emphasis, like:

• Mimi ninanunua... = I am buying...
• maybe implying not someone else

Ninanunua can be broken into parts:

• ni- = I
• -na- = present tense / ongoing action
• -nunua = buy

So:

• ni + na + nunua → ninanunua
• literally: I am buying / I buy

Depending on context, Swahili present tense can mean either I am buying or I buy.

Often, yes, but not only that. In many cases -na- marks present time and can translate into English in different ways depending on context:

• ninasoma = I am reading or I read
• anakula = he/she is eating or he/she eats

So in this sentence, ninanunua could mean:

• I am buying
• I buy

If the situation is happening right now, I am buying is the most natural translation.

Nguo is one of those Swahili nouns whose form often stays the same in singular and plural.

So:

• nguo can mean a garment/clothing item
• nguo can also mean clothes

You understand singular or plural from context.

This is normal in Swahili. Not every noun changes form visibly between singular and plural.

Adjectives in Swahili usually agree with the noun class of the noun they describe.

Here, nguo belongs to the N-class, and adjectives with this class often take the form n-/nz-.

So:

• nguo nzuri = nice clothes
• nyumba nzuri = nice house
• barua nzuri = nice letter

That is why you get nzuri, not zuri.

Nzuri is a very common adjective meaning things like:

• good
• nice
• beautiful
• fine

In nguo nzuri, the most natural meaning is:

• nice clothes
• possibly good clothes or beautiful clothes, depending on context

So the adjective has a broad positive meaning, and English translation depends on the situation.

The ending -ni is a locative ending. It often gives the meaning:

• in
• at
• to
• on

depending on the context.

So:

• soko = market
• sokoni = at the market / in the market

In this sentence, sokoni means at the market.

Yes. Swahili word order is fairly flexible, although some orders sound more neutral than others.

These are all possible:

• Mimi ninanunua nguo nzuri sokoni
• Sokoni, mimi ninanunua nguo nzuri
• Mimi sokoni ninanunua nguo nzuri

The most neutral and straightforward order here is the original one. Moving sokoni usually changes emphasis rather than the core meaning.

Swahili does not have articles like English a/an and the.

So nguo nzuri can mean:

• nice clothes
• the nice clothes
• some nice clothes

and sokoni can mean:

• at a market
• at the market

The exact meaning depends on context.

Yes, it can. The present form with -na- can describe:

• an action happening now
• a general or habitual action

So this sentence could mean either:

• I am buying nice clothes at the market
  or
• I buy nice clothes at the market

Context tells you which one is intended.

Yes, absolutely. That is a very natural sentence.

Because ni- already means I, the pronoun mimi can be dropped. In fact, leaving out subject pronouns is very common in Swahili.

So:

• Ninanunua nguo nzuri sokoni = natural, common
• Mimi ninanunua nguo nzuri sokoni = also correct, but more emphatic

Yes. In Swahili, adjectives usually come after the noun they describe.

So:

• nguo nzuri = literally clothes nice
• mtoto mdogo = small child
• kitabu kikubwa = big book

This is different from English, where adjectives usually come before the noun.

Yes. Swahili subject pronouns can be used for emphasis in a way that feels stronger than plain English I.

So Mimi ninanunua... can sound like:

• I am the one buying...
• As for me, I am buying...
• Me, I am buying...

The exact force depends on tone and context. Without special emphasis, it may simply sound slightly more explicit than necessary.