Njegere zikichemka haraka, chakula kitaiva mapema.

In Swahili, if/when/while can be built into the verb itself with -ki-.

So zikichemka breaks down like this:

• zi- = they, for the noun class of njegere
• -ki- = if / when / while
• -chemka = boil

So Swahili does not need a separate standalone word for if here.

Because the first clause is a conditional or time clause, not a simple future statement.

In Swahili, when you use -ki-, you normally do not also use the future marker -ta- in that same verb. So:

• zikichemka = if/when they boil
• zitachemka = they will boil

The future/result part appears in the main clause:

• chakula kitaiva mapema = the food will be ready early

So the pattern is:

• condition/time clause: zikichemka
• main future result: kitaiva

Because in this sentence njegere is being treated as a plural noun in noun class 10, and the subject marker for that class is zi-.

A useful thing to know is that many Swahili nouns in classes 9/10 look the same in singular and plural. The agreement on the verb tells you the number.

So here:

• njegere zikichemka = the njegere, if they boil...

If it were singular, you would expect a singular agreement marker instead.

Chakula is a class 7 singular noun, and the subject marker for class 7 is ki-.

So:

• ki- = subject marker agreeing with chakula
• -ta- = future
• -iva = become cooked / become ready

That gives kitaiva = it will be ready / it will cook.

This kind of agreement is very important in Swahili. The verb changes to match the noun class of its subject.

Literally, kitaiva means it will become ripe/cooked/ready.

The verb -iva often means ripen, but with food it can also mean:

• be cooked
• be done
• be ready to eat

So in this sentence, chakula kitaiva means that the food or meal will be ready / will cook through.

They are related, but they are not the same.

• haraka = quickly, fast
  This describes speed
• mapema = early, sooner
  This describes time

So the sentence is making a neat distinction:

• njegere zikichemka haraka = the njegere boil quickly
• chakula kitaiva mapema = the food will be ready early

In other words, something happens fast, so the result comes earlier.

This is a very common question.

• -chemka = boil, be boiling, come to a boil
  This is usually intransitive
• -chemsha = boil something
  This is transitive

Examples:

• Maji yanachemka = The water is boiling
• Ninachemsha maji = I am boiling the water

In your sentence, njegere zikichemka uses -chemka because the idea is that the njegere are boiling/cooking, not that they are boiling something else.

Yes. The -ki- form is flexible and can often mean:

• if
• when
• while

The exact English choice depends on context.

So njegere zikichemka haraka could be understood as:

• if the njegere boil quickly
• when the njegere boil quickly

If the sentence is giving a general cause-and-effect idea, English might use either one depending on style.

The order used here is very natural:

• condition first: Njegere zikichemka haraka
• result second: chakula kitaiva mapema

This is similar to English sentences like:

• If X happens, Y will happen

Swahili often puts the condition or time clause first, especially when it sets up the result clearly. The meaning comes mainly from the verb forms and agreement, not just from word order, but this order is the most straightforward here.