Dalili zikionekana tena, tafadhali nenda kliniki mara moja.

Dalili can be either singular or plural in Swahili, depending on context.

• singular: dalili = a symptom / a sign
• plural: dalili = symptoms / signs

This is common with N/N class nouns, where the singular and plural often look the same.
You tell whether it is singular or plural from the verb agreement.

Here, the verb starts with zi-, which is a plural agreement marker, so dalili must mean symptoms in this sentence.

Zikionekana can be broken down like this:

• zi- = subject marker for plural dalili
• -ki- = if/when marker
• -onekana = be seen / appear / become visible

So literally it means something like:

if they are seen
or more naturally: if they appear

In this sentence, Dalili zikionekana tena means if the symptoms appear again or if symptoms reappear.

The -ki- tense marker often expresses if, when, or whenever.

So:

• zikionekana = if they appear / when they appear

In practical instructions like this, English may translate it as either if or when, depending on the tone:

• If symptoms appear again, please go...
• When symptoms appear again, please go...

Here, if is usually the most natural English choice.

Yes—literally, onekana comes from ona (see) and means be seen / be visible.

But in natural usage, be seen can easily become appear or show up, especially with things like symptoms, signs, or problems.

So:

• dalili zinaonekana = the symptoms are visible / can be seen
• in context, this often becomes the symptoms appear

That is why zikionekana tena is idiomatically understood as if they appear again.

Tena means again.

So:

• zikionekana = if they appear
• zikionekana tena = if they appear again

It tells you that the symptoms had already happened before and have now returned.

Nenda is the imperative form, used to give a direct instruction to one person:

• nenda = go

Kwenda is the infinitive:

• kwenda = to go

So in this sentence, the speaker is giving advice or an instruction:

tafadhali nenda kliniki mara moja
= please go to the clinic immediately

If speaking to more than one person, you would usually say:

• nendeni = go (plural)

In Swahili, after verbs of motion like nenda (go), the destination often comes directly without a separate word for to.

So:

• nenda kliniki = go to the clinic
• literally, it looks like go clinic

This is normal Swahili structure. English needs to, but Swahili often does not.

Mara moja means immediately, right away, or at once.

Word-for-word, it is literally something like one time, but as a fixed expression it means:

• immediately
• without delay

So:

tafadhali nenda kliniki mara moja
= please go to the clinic immediately

Tafadhali means please.

It makes the instruction more polite:

• nenda kliniki mara moja = go to the clinic immediately
• tafadhali nenda kliniki mara moja = please go to the clinic immediately

It can appear in different positions in a sentence, but here it comes naturally before the command.

It is grammatically a command/instruction, because of nenda.

But in real-life use, it sounds more like medical advice or a warning, especially because of the context:

Dalili zikionekana tena, tafadhali nenda kliniki mara moja.

So the tone is:

• direct enough to be clear
• polite because of tafadhali
• urgent because of mara moja

Yes, a Swahili learner may hear alternatives such as zikitokea tena.

• kutokea = to occur / happen / appear
• kuonekana = to be seen / appear

So:

• Dalili zikitokea tena... = If symptoms occur again...
• Dalili zikionekana tena... = If symptoms appear again...

Both are understandable.
The version with zikionekana emphasizes the symptoms becoming visible/noticed, while zikitokea emphasizes them occurring.