Yeye anasoma kitabu chake jioni.

A word-by-word breakdown is:

• Yeye = he/she
• anasoma = is reading / reads
• kitabu = book
• chake = his/her
• jioni = in the evening / evening

So the sentence means something like He/She is reading his/her book in the evening or He/She reads his/her book in the evening, depending on context.

Yes. In Swahili, the verb already includes a subject marker.

In anasoma:

• a- = he/she
• -na- = present tense
• -soma = read

So anasoma by itself already means he/she is reading or he/she reads.

That means yeye is often optional. It is usually added for emphasis, contrast, or clarity. For example:

• Anasoma kitabu chake jioni = He/She reads his/her book in the evening
• Yeye anasoma kitabu chake jioni = He/She reads his/her book in the evening, with extra emphasis on the person

Anasoma can be divided into three parts:

• a- = subject marker for he/she
• -na- = present tense marker
• -soma = verb root meaning read/study

So:

• a + na + soma = anasoma

This is a very common Swahili pattern: subject marker + tense marker + verb root

For example:

• ninasoma = I am reading
• unasoma = you are reading
• anasoma = he/she is reading
• wanasoma = they are reading

It can mean both, depending on context.

Anasoma with -na- is often used for:

• an action happening now: is reading
• a habitual action: reads

So this sentence could mean:

• He/She is reading his/her book this evening
• He/She reads his/her book in the evening

The time word jioni helps shape the meaning, but context is still important.

Because Swahili possessives must agree with the noun class of the thing being possessed.

Kitabu belongs to the ki-/vi- noun class. With this class, the possessive stem -ake becomes chake.

So:

• kitabu chake = his/her book

You can compare:

• kitabu chake = his/her book
• vitabu vyake = his/her books

The possessive changes to match the noun, not the owner.

It can mean either his or her.

Swahili does not usually mark gender in the third person singular. So:

• yeye = he or she
• a- in anasoma = he or she
• chake = his or her

You need context to know whether the person is male or female.

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

So kitabu can mean:

• a book
• the book
• sometimes just book, depending on context

In this sentence, kitabu chake is naturally understood as his/her book. English needs an article system, but Swahili does not.

In Swahili, many time expressions can appear directly without a separate preposition.

So jioni by itself can mean:

• in the evening
• this evening
• during the evening

This is very normal in Swahili. Similar time words often work the same way.

For example:

• asubuhi = in the morning
• mchana = in the daytime / afternoon
• usiku = at night
• jioni = in the evening

The basic word order here is:

Subject + Verb + Object + Time

So:

• Yeye = subject
• anasoma = verb
• kitabu chake = object
• jioni = time expression

This is a very common and natural order in Swahili.

However, Swahili can sometimes move parts around for emphasis. For example, dropping yeye is very common:

• Anasoma kitabu chake jioni

That sounds completely natural too.

Yeye is used for a person: he/she.

It is not normally used for inanimate things like book, table, or car. Swahili uses noun-class agreement for things, rather than separate pronouns like English it in the same way.

So in this sentence, yeye clearly refers to a person who is doing the reading.

Yes. -soma can mean read or study, depending on context.

Examples:

• anasoma kitabu = he/she is reading a book
• anasoma shule or similar educational contexts = he/she is studying

In your sentence, because the object is kitabu chake (his/her book), the most natural meaning is read.