Jimbo hili ni kubwa.

Because Swahili demonstratives have to agree with the noun class of the noun they describe.

Jimbo is a singular noun in noun class 5, so this becomes hili.

So:

• jimbo hili = this state/region/province

If the noun were in a different class, this would look different, such as huyu, hii, hizi, and so on.

Ni is the copula here, meaning is.

So the structure is:

• Jimbo hili = this state/region/province
• ni = is
• kubwa = big/large

Together: Jimbo hili ni kubwa = This state/region/province is big.

A useful thing to know is that ni does not change for person or number in this kind of simple sentence:

• Mimi ni... = I am...
• Yeye ni... = he/she is...
• Majimbo haya ni... = these states/regions are...

In Swahili, demonstratives usually come after the noun, not before it as in English.

So English says:

• this region

But Swahili says:

• jimbo hili
• literally: region this

This is completely normal Swahili word order.

Because kubwa is the predicate adjective here: it tells you what the subject is like.

The pattern is:

• noun phrase + ni + adjective

So:

• Jimbo hili ni kubwa = This region is big.

Compare that with:

• jimbo kubwa = a big region / the big region

That version has no ni, so it is just a noun plus adjective inside one noun phrase, not a full is sentence.

It does agree, but in this noun class the agreement is not very visible.

The adjective stem is -kubwa. With jimbo (class 5 singular), the form is simply kubwa.

In the plural, you can see the agreement more clearly:

• jimbo kubwa = big region
• majimbo makubwa = big regions

So in Jimbo hili ni kubwa, the adjective is correctly matched to a class 5 singular noun.

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

Whether something is understood as a region, the region, or this region depends on context and on words like demonstratives.

In this sentence, hili already makes the noun specific:

• jimbo hili = this region/state/province

So there is no need for a separate word meaning the.

The plural is:

• Majimbo haya ni makubwa.

That means These states/regions/provinces are big.

Changes:

• jimbo → majimbo
• hili → haya
• kubwa → makubwa

This shows how Swahili noun classes affect several words in the sentence, not just the noun itself.

Usually, no.

If you say:

• Jimbo hili kubwa

that does not sound like the normal way to say This region is big. It sounds incomplete or like you are trying to build a noun phrase.

To clearly say is big, use:

• Jimbo hili ni kubwa

A very important contrast is:

• jimbo kubwa = a big region / the big region
• Jimbo hili ni kubwa = this region is big

So ni helps show that you are making a full statement.

A simple pronunciation guide is:

• JIM-bo HEE-lee nee KOO-bwa

A few tips:

• ji sounds like the ji in jeep, but shorter
• mb is pronounced together, like in number
• hili has a clear h
• kubwa has two parts: ku-bwa
• Swahili stress usually falls on the second-to-last syllable

So:

• JIM-bo
• HEE-li
• KOO-bwa