Meza iko sebuleni, na kitabu kiko juu yake.

Because the verb form has to agree with the noun class of the subject.

• meza belongs to noun class 9/10, so it takes the subject prefix i-
• kitabu belongs to noun class 7/8, so it takes the subject prefix ki-

So:

• meza iko sebuleni = the table is in the living room
• kitabu kiko juu yake = the book is on top of it

You can think of these as:

• i-ko
• ki-ko

The -ko part stays the same here, and the first part changes to match the noun.

Here, -ko is a locative form used when talking about where something is.

So:

• iko roughly means it is there / it is located
• kiko also roughly means it is there / it is located, but with a different noun class agreement

In other words, these are not random forms. They are built from:

• a subject prefix: i-, ki-, etc.
• plus -ko, which gives the sense of being in a place

That is why this sentence sounds natural for location:

• Meza iko sebuleni = The table is in the living room

The ending -ni is a very common locative ending in Swahili. It often means something like:

• in
• at
• inside
• to a place, depending on context

So:

• sebule = living room
• sebuleni = in the living room

This is one of the most useful patterns in Swahili for talking about location.

Literally, juu yake means on top of it.

Breakdown:

• juu = top / upper part / above
• ya = a linker used here in the expression juu ya ...
• -ke = his/her/its

So juu yake is understood as on top of it in this sentence.

In natural English, we translate:

• kitabu kiko juu yake = the book is on it or the book is on top of it

Because in juu yake, the agreement is not being made with kitabu. It refers back to meza.

• meza is class 9
• the possessive form used with class 9 here is yake

So juu yake means on top of it, where it = the table

If you used chake, that would agree with a class 7 noun such as kitabu, which would change the meaning.

Yes, absolutely.

These are both natural:

• kitabu kiko juu yake = the book is on top of it
• kitabu kiko juu ya meza = the book is on top of the table

The second version repeats meza, while the first uses yake to refer back to it.

English does the same kind of thing:

• The book is on top of it
• The book is on top of the table

In Swahili, the idea of is is built into forms like iko and kiko.

So you should not expect a separate word exactly like English is in every sentence.

Here:

• iko = is located
• kiko = is located

That means:

• Meza iko sebuleni is already a complete sentence
• Kitabu kiko juu yake is also a complete sentence

na here means and.

So the sentence is simply joining two statements:

• Meza iko sebuleni = The table is in the living room
• na
• kitabu kiko juu yake = and the book is on top of it

Be careful: na can also mean with in other contexts, but here it clearly means and.

Yes, the basic word order here is the normal Swahili pattern:

• subject + verb + place

So:

• Meza iko sebuleni
• kitabu kiko juu yake

This is the clearest and most neutral order for a learner to use.

Swahili does allow some flexibility for emphasis, but this standard order is the one you should learn first.

That is a very normal learner question. In Swahili, noun class is not always obvious just from the form of the word.

meza is treated as a class 9/10 noun, so it takes class 9 agreement in the singular:

• meza iko ...

Many borrowed nouns behave this way. So even if the shape of the word does not clearly show its class, the agreement tells you how it behaves.

That is one reason it is useful to learn nouns together with example agreement:

• meza iko
• kitabu kiko

In some contexts, Swahili uses several locative patterns, and advanced learners will notice forms connected with different locative classes. But in this sentence, iko and kiko are the normal, straightforward forms for saying where something is.

So for a beginner, the most important thing is:

• iko / kiko are natural for is located
• sebuleni shows the place
• juu yake shows the position relative to the table

You do not need to master the full locative system to understand this sentence correctly.