Learn Hardcore Indonesian: Adik saya baru membuka buku, sudah mengeluh capek belajar. - My younger sibling had just opened a book and was already complaining of being tired of studying.

Adik saya baru membuka buku ≈ “My younger sibling has only just opened the book.”
It does not mark tense like English past or present; Indonesian doesn’t have grammatical tense the way English does.
Instead, baru marks the recency of the action: it happened very recently or has barely even started.

So it emphasizes that the action of opening the book has only just begun.

Then why is sudah also used? Isn’t baru kind of opposite to sudah?

Yes, literally baru (“just now”) and sudah (“already”) can seem opposite, and that’s exactly what gives this sentence its flavor.

Baru membuka buku: has only just opened the book.
Sudah mengeluh: is already complaining.

Putting them together creates a contrastive meaning:

Even though they’ve just opened the book, they’re already complaining.

This combination is common in Indonesian: using baru in the first clause and sudah in the second to show something happens too quickly / too soon, often with a bit of annoyance or criticism.

Why is there no subject like dia in the second part (sudah mengeluh capek belajar)?

Indonesian often drops the subject when it’s clear from context.

First clause: Adik saya baru membuka buku
Second clause: sudah mengeluh capek belajar

The subject Adik saya is still understood for the second clause, so it doesn’t need to be repeated:

Full, explicit version: Adik saya baru membuka buku, (dia) sudah mengeluh capek belajar.
Natural, actual sentence: subject omitted in the second clause.

This is very normal and sounds more natural in everyday Indonesian.

What exactly does mengeluh mean, and is it always negative?

Mengeluh means “to complain / to grumble / to whine”.

It’s usually negative or at least mildly negative: it implies someone is not just stating a fact but doing so in a complaining tone.
In this sentence, it shows the speaker’s mild criticism or impatience with the younger sibling’s attitude.

So sudah mengeluh is like “is already complaining / whining (about it).”

What is the role of capek here? Is it a verb like “to get tired”?

Capek is an adjective meaning “tired, exhausted”, especially in casual speech.

In mengeluh capek belajar, you can analyze it like this:

mengeluh = to complain
capek = (being) tired
belajar = to study

So it’s roughly: “complain (that he/she is) tired of studying / tired from studying.”
The “that” and the subject dia are understood, not stated:

Long version: mengeluh (bahwa dia) capek (karena) belajar
Spoken, natural version: mengeluh capek belajar

Why is there no untuk or karena between capek and belajar, like capek untuk belajar or capek karena belajar?

In everyday Indonesian, it’s very common to just stack words like this:

capek belajar
malas belajar (lazy to study)
senang bermain (happy to play)

Capek belajar is understood as:

“tired of studying”
or “tired from studying”, depending on context.

You can say:

capek karena belajar = tired because of studying
capek untuk belajar is unusual; it sounds off or unnatural.

But for casual speech, capek belajar is perfectly normal and very idiomatic.

Could this sentence also be “Adik saya baru membuka buku, sudah capek belajar.” without mengeluh?

Yes, that’s possible, and it’s still natural:

Adik saya baru membuka buku, sudah capek belajar.
= “My younger sibling has only just opened the book, and is already tired of studying.”

The nuance changes slightly:

With mengeluh: focuses on the complaining behavior.
Without mengeluh: simply states that they’re already tired (the complaining part is implied by context or tone, but not stated explicitly).

Both are fine; the original sentence just makes the complaining more explicit.

Why membuka buku and not membaca buku if the context is studying?

Membuka buku = “to open the book” (physically start, first step before reading).
Membaca buku = “to read the book.”

Using membuka buku here emphasizes how early the complaining starts:

They haven’t even really started reading/studying yet; they’ve just opened the book, and are already complaining.

If you said membaca buku, it would sound more like they were actually reading for a bit. Membuka buku makes the impatience / laziness clearer and more humorous or critical.

What exactly does adik saya refer to? Does it specify gender?

Adik = younger sibling (younger brother or younger sister; gender-neutral).
saya = my.

So adik saya = “my younger sibling”, without specifying gender.
If you need to specify gender, you could say:

adik laki-laki saya = my younger brother
adik perempuan saya = my younger sister

In everyday conversation, if context is clear, adik saya is enough.

Could I say “Adikku baru membuka buku…” instead of “Adik saya…”?

Yes, both are correct:

Adik saya = my younger sibling (more neutral/polite, slightly more formal).
Adikku = my younger sibling (more intimate, casual, often in speech, writing to friends or family).

The meaning is the same; you just choose based on formality and closeness to the listener/reader. The rest of the sentence stays the same:

Adikku baru membuka buku, sudah mengeluh capek belajar.

Is this sentence formal, informal, or neutral?

This sentence leans informal / conversational, mainly because of:

capek – casual; the more formal word is lelah.
The structure mengeluh capek belajar, with omissions, is common in speech.

A more formal-ish version could be:

Adik saya baru membuka buku, sudah mengeluh lelah belajar.

But as given, it’s very natural in everyday spoken Indonesian.

Could I reverse the order and say “Adik saya sudah mengeluh capek belajar, baru membuka buku”?

Grammatically, it’s understandable, but it sounds strange and unnatural in normal Indonesian.

The logic of the complaint is:
First: opens the book (baru membuka buku)
Immediately after: already complaining (sudah mengeluh…)

Reversing it (“already complaining, only just opened the book”) violates the natural time order and makes the sentence feel awkward. To keep the same meaning and naturalness, keep baru in the first clause and sudah in the second, as in the original.