Nilisoma marejeo katika kitabu.

Nilisoma can be broken into:

• ni- = I
• -li- = past tense marker
• -soma = read / study

So nilisoma literally means I read or I studied in the past.

In Swahili, the subject is usually built into the verb.
So instead of saying a separate word for I, you use the subject prefix ni-.

That means:

• Nilisoma = I read
• You do not need an extra mimi unless you want emphasis.

For example, Mimi nilisoma would mean something like I read with extra emphasis, as in I was the one who read.

It can mean both, depending on context.

• kusoma kitabu often means to read a book
• kusoma shule / chuo / somo fulani can mean to study

In Nilisoma marejeo katika kitabu, the context suggests read, because the object is something found in a book.

Marejeo is a noun. Depending on context, it can mean things like:

• references
• cross-references
• citations
• notes referring to something else

It is a plural noun. The singular is often rejeo.

So:

• rejeo = a reference
• marejeo = references

Because the noun has the plural prefix ma-, which is common in one of Swahili’s noun classes.

Here the pattern is:

• rejeo = singular
• marejeo = plural

A learner may notice that English often uses references in the plural too, so this matches the idea naturally in many contexts.

Katika usually means in, inside, within, or sometimes in the context of.

In this sentence, it marks location:

• katika kitabu = in the book

It is a common and fairly standard way to say in. In everyday speech, some speakers might also use kwenye in certain contexts, but katika is very natural and clear here.

Yes, in many contexts you may hear kwenye kitabu.

Very roughly:

• katika = in / inside / within
• kwenye = often on / at / in, depending on context

For a book, katika kitabu sounds very straightforward for in the book.
Kwenye kitabu may also be understood, but katika is often the safer choice for learners when talking about something contained in a book.

Because it refers to a book or the book, depending on context. Swahili does not use articles like a and the the way English does.

So kitabu can mean:

• a book
• the book

You understand which one is meant from context.

Also, kitabu is singular. Its plural is vitabu.

Kitabu belongs to the ki-/vi- noun class:

• kitabu = singular
• vitabu = plural

This is an important class in Swahili. Many nouns in this class take agreement patterns related to ki- in singular and vi- in plural.

Swahili has no articles equivalent to English a/an and the.

So:

• kitabu can mean a book or the book
• marejeo can mean references or the references

Context tells you which interpretation is intended.

This is a very normal word order in Swahili:

• Nilisoma = verb
• marejeo = object
• katika kitabu = location / place phrase

So the pattern is:

subject-in-verb + verb root + object + location

Swahili word order can be changed for emphasis, but this sentence uses a very standard and natural order.

No, that would sound wrong if you mean references in the book.

You need katika to show the relationship clearly:

• marejeo katika kitabu = references in the book

Without katika, it may sound like marejeo and kitabu are just two nouns placed together without a clear connection.

You would usually use the present marker -na-:

• Ninasoma marejeo katika kitabu.

That means I am reading references in the book or I read references in the book, depending on context.

Compare:

• nilisoma = I read / I was reading
• ninasoma = I am reading / I read
• nimesoma = I have read / I have studied

This is a very common learner question.

• nilisoma = simple past, I read / I studied
• nimesoma = perfect, I have read / I have studied

So:

• Nilisoma marejeo katika kitabu = you are talking about a past action
• Nimesoma marejeo katika kitabu = you are emphasizing completion or a result relevant now

A simple pronunciation guide:

• Ni-li-so-ma ma-re-je-o ka-ti-ka ki-ta-bu

Swahili pronunciation is usually very regular.
Each vowel is pronounced clearly:

• a as in father
• e as in bed but often a bit clearer
• i as in machine
• o as in more but pure
• u as in rule

Most syllables are open, ending in vowels, which gives Swahili its smooth rhythm.