Daktari anasema chakula chake kinapaswa kubadilishwa ili kuboresha afya yake.

It comes from the verb -sema, meaning to say / speak.

Breakdown:

• a- = he/she
• -na- = present or ongoing time
• -sema = say

So anasema means he/she says or he/she is saying.

Because daktari can refer to a male or female doctor, anasema does not tell you the doctor’s gender.

In Swahili, the word kwamba = that is often omitted after verbs like say, know, or think.

So both of these are natural:

• Daktari anasema chakula chake...
• Daktari anasema kwamba chakula chake...

English usually wants that more often, but Swahili often leaves it out.

Because Swahili possessives agree with the thing possessed, not with the owner.

Here, the possessed noun is chakula (food / diet), which is a ki-/vi- class noun in the singular. That means the possessive uses cha-.

So:

• chakula chake = his/her food or his/her diet

The -ke part means his/her.
The cha- part matches chakula.

So chake is the correct agreement form here.

Because the verb must agree with chakula.

Chakula is singular in the ki-/vi- noun class, so the subject marker is ki-.

Breakdown:

• ki- = it, referring to chakula
• -na- = present
• -paswa = be supposed to / ought to

So kinapaswa means it should or more literally it is supposed to.

That is why Swahili does not use a general word like English should for every subject; the verb changes to match the noun class.

-paswa expresses obligation or what is considered appropriate.

So:

• kinapaswa = it should
• more literally: it is supposed to / it ought to

This is a very common way to express should in Swahili.

Because the sentence needs a passive meaning.

• kubadilisha = to change something
• kubadilishwa = to be changed

Here, chakula chake is receiving the action. The food/diet is not doing the changing; it is the thing being changed.

So:

• chakula chake kinapaswa kubadilishwa = his/her diet should be changed

The -w- in kubadilishwa is the passive marker.

Ili means so that or in order to.

It introduces the purpose of the change:

• ili kuboresha afya yake = in order to improve his/her health

So the idea is:

• the diet should be changed
• for the purpose of improving health

Kuboresha means to improve or to make better.

So:

• kuboresha afya yake = to improve his/her health

It is the infinitive form, marked by ku-:

• ku- = to
• -boresha = improve / make better

Again, the possessive must agree with the noun being possessed.

Here the noun is afya (health), not chakula.

With afya, the correct possessive form is yake:

• afya yake = his/her health

So the sentence has two different possessive forms because there are two different nouns:

• chakula chake = his/her diet
• afya yake = his/her health

This is very normal in Swahili.

Literally, chakula means food, but in this sentence diet is the more natural English meaning.

Because the context is a doctor talking about improving someone’s health, chakula chake is likely referring to:

• what the person eats regularly
• eating habits
• diet

So even though the basic word is food, the best translation here is often diet.

By themselves, chake and yake just mean his/her. Swahili does not mark gender here, and the sentence alone does not force one interpretation.

In context, it usually refers to the person whose health is being discussed, not necessarily the doctor. So the meaning is often something like:

• The doctor says that his/her diet should be changed in order to improve his/her health.

If you need to know exactly whose diet and health are meant, you usually depend on context.

Yes, roughly like this:

• Daktari = doctor
• anasema = says / is saying
• chakula chake = his/her food, his/her diet
• kinapaswa = it should / it is supposed to
• kubadilishwa = be changed
• ili = in order to / so that
• kuboresha = improve
• afya yake = his/her health

A very literal version would be:

Doctor says his/her food/diet it-should be-changed in-order-to improve his/her health.

That sounds awkward in English, but it helps show how the Swahili grammar works.