Learn Hardcore Indonesian: Gejala utama saya adalah batuk ringan dan tenggorokan kering. - My main symptom is a mild cough and a dry throat.

So saya goes at the end of the whole noun phrase, after gejala utama.
You could also say gejala saya yang utama, but that sounds more like “the symptom of mine that is the main one” – a bit heavier; gejala utama saya is simpler and more natural here.

What is the function of adalah here? Is it necessary?

Adalah works like the linking verb “is/are” when you link a noun phrase to another noun/adjective phrase, especially in more formal or written Indonesian.

In this sentence:

Gejala utama saya → subject
adalah → “is”
batuk ringan dan tenggorokan kering → complement

You can often omit adalah, especially in spoken or less formal language:

Gejala utama saya batuk ringan dan tenggorokan kering.

Both versions are correct. With adalah feels a bit more formal or written.

Can I completely drop saya and just say Gejala utama adalah batuk ringan dan tenggorokan kering?

Yes, grammatically that is fine: Gejala utama adalah batuk ringan dan tenggorokan kering = The main symptoms are mild cough and dry throat.

However, you then lose the idea of “my”. It sounds more general, like you are talking about “the main symptoms (in general) are…”, not specifically your own.

With saya: clearly my main symptom(s)
Without saya: could be read as general information

What nuance does batuk ringan have? Is it “light cough” or “mild cough”? Could I say sedikit batuk instead?

Batuk ringan is usually best translated as “mild cough” (or “light cough”). It suggests the severity is low.

ringan literally = light (not heavy) → mild, not serious

Sedikit batuk literally means “a little (bit of) cough” and focuses more on quantity/frequency than severity. It’s understandable, but less standard as a symptom description.

As a clinical-style symptom description, batuk ringan is the most natural phrase.

Why don’t we say batuk yang ringan or tenggorokan yang kering?

Indonesian often puts adjectives directly after the noun without yang:

batuk ringan = mild cough
tenggorokan kering = dry throat

Yang is mainly used to:

introduce a relative clause:
- batuk yang membuat saya susah tidur = cough that makes it hard for me to sleep
or sometimes to emphasize / make the phrase heavier:
- batuk yang ringan (a cough that is mild)

In simple noun + adjective phrases (like in this symptom list), yang is normally omitted. Adding yang here would sound more like you’re making a contrast or emphasizing: “a cough which is mild” rather than just “mild cough”.

Why don’t we say tenggorokan saya kering instead of tenggorokan kering? What’s the difference?

Both are possible, but they sound slightly different:

tenggorokan kering = “dry throat” (as a general symptom label)
tenggorokan saya kering = “my throat is dry” (more like a full sentence about your throat)

In Gejala utama saya adalah batuk ringan dan tenggorokan kering, the part after adalah is a list of symptom names, like labels on a chart:

mild cough
dry throat

If you say …batuk ringan dan tenggorokan saya kering, it mixes a symptom label (batuk ringan) with a full clause-like phrase (tenggorokan saya kering) and sounds less balanced. As a neat symptom list, batuk ringan dan tenggorokan kering is more natural.

Why isn’t there any word for “a” or “the” in this sentence?

Indonesian generally does not use articles like a/an or the. Whether something is definite or indefinite is usually understood from context.

So:

batuk ringan can be “a mild cough” or “mild cough”
tenggorokan kering can be “a dry throat” or “dry throat”
gejala utama saya can be “my main symptom” or “the main symptom I have”

You choose a/the in English when translating, but Indonesian simply doesn’t mark that.

Should it be gejala-gejala utama saya if I have more than one symptom?

You don’t need to mark the plural here. Indonesian often leaves nouns unmarked for plural, and plurality is inferred from context.

gejala saya = my symptom / my symptoms
gejala utama saya = my main symptom / my main symptoms

You could say gejala-gejala utama saya to clearly show “my main symptoms (plural)”, but in everyday usage, gejala utama saya already feels natural even if you then list several symptoms afterwards, as in this sentence.

How formal is saya here? Could I use aku instead?

Saya is the default polite / neutral pronoun for “I” in most situations, especially:

with doctors, strangers, or in writing
in anything semi-formal or formal

Aku is more informal / intimate, used with:

close friends, family, partners
casual situations

In a medical context or describing symptoms to a doctor, Gejala utama saya adalah… is more appropriate and natural than Gejala utama aku adalah….