Jioni nitaenda famasi kununua sharubati kwa sababu mafua hayajaisha.

Jioni means in the evening / this evening / evening time.

It is often placed at the beginning of the sentence to set the time right away, just like English can do with Tonight or In the evening.

So:

• Jioni nitaenda... = This evening I will go...

You could move it later in some contexts, but putting time expressions first is very natural in Swahili.

Nitaenda breaks down as:

• ni- = I
• -ta- = future marker, will
• -enda = go

So:

• nitaenda = I will go

This is a very common Swahili verb pattern:

• ni-ta-soma = I will read/study
• u-ta-kuja = you will come
• a-ta-fanya = he/she will do

In Swahili, verbs of motion like kwenda (to go) often do not need a separate word for to before a place.

So:

• nitaenda famasi = I will go to the pharmacy

This is normal Swahili structure.

You may also hear:

• nitaenda kwenye famasi
• nitaenda kwa famasi in some varieties

But simply saying nitaenda famasi is very natural and common.

Yes, famasi is a borrowed and commonly understood word for pharmacy.

Another very common expression is:

• duka la dawa = drugstore / pharmacy

Depending on region and speaker, one form may be more common than the other. A learner should recognize both.

Kununua is the infinitive to buy.

After a verb of motion like go, Swahili often uses the infinitive to show purpose:

• nitaenda famasi kununua sharubati
• literally: I will go pharmacy to buy syrup

This works a lot like English to buy in I will go to the pharmacy to buy syrup.

Other examples:

• Nimekuja kusaidia. = I have come to help.
• Alienda kusoma. = He/she went to study.

Sharubati literally refers to syrup.

Depending on context, it can mean:

• sweet syrup
• medicinal syrup
• cough syrup / liquid medicine

In this sentence, because the speaker is going to the pharmacy and mentions mafua, sharubati most likely means medicine syrup, probably something like cough syrup or cold syrup.

So the exact English translation may vary a little depending on context.

Kwa sababu means because.

It introduces a reason:

• Nitaenda famasi ... kwa sababu mafua hayajaisha.
• I will go to the pharmacy ... because the cold has not gone away.

It is a very common connector in Swahili.

Other examples:

• Sikuja kwa sababu nilikuwa mgonjwa. = I didn’t come because I was sick.
• Anasoma kwa sababu ana mtihani. = He/she is studying because he/she has an exam.

This is a very common learner question.

Mafua is the usual Swahili word for a cold / flu-like cold / runny-nose illness, even though its form looks plural.

In other words, Swahili treats this illness word differently from English. English says:

• I have a cold

But Swahili says:

• Nina mafua

So even when the meaning in English is singular, the Swahili noun mafua belongs to a noun class that takes plural-type agreement.

That is why later in the sentence you get:

• mafua hayajaisha

not a singular agreement form.

This is one of the most important grammar points in the sentence.

Hayajaisha can be broken down like this:

• ha- = negative
• -ya- = subject marker for the noun class of mafua
• -ja- = negative perfect marker, roughly have not
• -isha = finish/end

So:

• mafua hayajaisha = the cold has not ended / the symptoms have not gone away yet

This is why the verb may look long: Swahili packs a lot of information into one word.

Good question. The meanings are related but not the same.

• hayajaisha = have not ended yet / have not gone away
• hayaishi = do not end / are not ending / do not usually finish

In this sentence, hayajaisha is better because the speaker means the cold is still continuing up to now.

So it is not a general truth like colds do not end. It is a current situation: my cold hasn’t gone away yet.

Because Swahili verbs agree with the noun class of the subject.

Mafua belongs to the ma-/ya- class, so the subject marker is ya.

That is why you get:

• mafua yameisha = the cold has ended / the symptoms are gone
• mafua hayajaisha = the cold has not ended

This noun class agreement is very important in Swahili grammar.

Yes. In context, that is a very natural interpretation.

Swahili often leaves out possessives when they are obvious from context. If the speaker says they are going to buy syrup because mafua hayajaisha, listeners will usually understand:

• my cold hasn’t gone away yet

If you wanted to make it explicit, you could say:

• mafua yangu hayajaisha = my cold hasn’t gone away

But the shorter version is completely normal.

Yes, it is natural and understandable everyday Swahili.

A few small variations are also possible, for example:

• Jioni nitaenda duka la dawa kununua sharubati kwa sababu mafua hayajaisha.
• Leo jioni nitaenda famasi kununua sharubati kwa sababu mafua yangu hayajaisha.

These do not change the basic grammar much. They just make the place or possession a little more explicit.