Learn Hardcore Indonesian: Setelah belajar seharian, adik perempuan saya tetap percaya diri. - After studying all day, my younger sister still feels confident.

In Indonesian, adik means “younger sibling” (gender-neutral) and perempuan means “female.” Together, adik perempuan means “younger sister.” Without perempuan, adik saya could mean either a younger brother or sister. For older siblings, use kakak (e.g., kakak perempuan = older sister, kakak laki-laki = older brother).

Can I just say adik saya instead of adik perempuan saya?

Yes, but then the gender is unspecified. If you want to be clear it’s a sister, keep perempuan (you could also say adik cewek in casual speech). For a younger brother, say adik laki-laki.

Why is there a comma after Setelah belajar seharian? Can I move that clause?

When a time clause comes first, Indonesian typically uses a comma: Setelah belajar seharian, … If you place it after the main clause, no comma is needed: Adik perempuan saya tetap percaya diri setelah belajar seharian. Both word orders are natural.

Who is the subject of belajar in Setelah belajar seharian?

It’s understood to be the same as the subject of the main clause, so here it’s the younger sister. Indonesian often omits the subject in fronted time clauses if it’s the same as the main subject. If it’s different, make it explicit:

Same subject: Setelah (adik perempuan saya) belajar seharian, adik perempuan saya tetap percaya diri.
Different subject: Setelah saya belajar seharian, adik perempuan saya tetap percaya diri.

What’s the difference between setelah and sesudah (or sehabis, habis, usai)?

Setelah and sesudah are near-perfect synonyms meaning “after.” Sehabis/habis is more colloquial. Usai is a bit literary/formal. All can introduce a clause or a noun phrase: setelah makan, sesudah rapat, sehabis hujan, usai pertandingan.

What does seharian mean exactly? How is it different from sehari-hari or sepanjang hari?

Seharian = “all day (long).” It’s built from se- + hari + -an and functions as a duration adverb.

seharian: all day long (one day’s entire duration)
sehari-hari: every day, daily (habitual)
sepanjang hari / sehari penuh: synonyms of “all day,” slightly more explicit/formal
You could also say selama sehari (“for one day”), which is neutral but less idiomatic than seharian for “all day long.”

Is belajar transitive? When would I use mempelajari?

Belajar is typically intransitive (“to study/learn”), but you can add a topic without needing a special object marker: belajar matematika. Mempelajari is transitive and must take a specific object: Saya mempelajari kimia. Both are fine in this context: Setelah belajar matematika seharian or Setelah mempelajari matematika seharian (the latter sounds more formal/specific).

Can I say Setelah seharian belajar instead of Setelah belajar seharian?

Yes. Setelah seharian belajar and Setelah belajar seharian are both natural. The difference is minimal; some speakers feel seharian belajar foregrounds the length a touch more, but it’s mostly stylistic.

What’s the nuance of tetap compared to masih or terus?

tetap = “remain/stay” (often despite a change or expectation): tetap percaya diri implies she remained confident even though studying all day could have made her tired or doubtful.
masih = “still (continuing to be)”: masih percaya diri states continuity without the “despite” nuance.
terus = “continuously/keep on (doing something)” and doesn’t fit here to describe a state; it’s more for ongoing actions: terus belajar (“keep studying”).

Is percaya diri an adjective or a noun? How does it relate to yakin or kepercayaan diri?

Percaya diri behaves like an adjective meaning “confident”: Dia percaya diri. The noun is kepercayaan diri (“self-confidence”): Kepercayaan dirinya tinggi. Yakin means “sure/certain (about something)” and takes a complement: Dia yakin (bahwa) jawabannya benar. Colloquially, pede/PD is slang derived from percaya diri.

Could I say tetap merasa percaya diri?

Yes, tetap merasa percaya diri is grammatical and emphasizes the subjective feeling (“continues to feel confident”). In most cases, tetap percaya diri is more concise and idiomatic unless you specifically want to highlight the feeling.

Is perempuan interchangeable with wanita or cewek?

perempuan: neutral/common and widely preferred (inclusive tone).
wanita: formal and often used in institutional or respectful contexts (e.g., pegawai wanita), but some prefer perempuan in general usage.
cewek: casual slang (“girl/chick”), not for formal contexts.
In your sentence, adik perempuan is the best neutral choice.

Can I use aku or gue instead of saya here?

Yes, but keep the register consistent.

Neutral/formal: adik perempuan saya
Neutral/informal: adik perempuanku or adikku
Colloquial Jakarta: adik perempuan gue / adik gue
Using the enclitic -ku (e.g., adikku, adik perempuanku) is the most natural with aku in standard Indonesian. Separate adik perempuan aku is common in speech but less preferred in formal writing.

How would I negate this sentence?

Use tidak before the predicate: Setelah belajar seharian, adik perempuan saya tetap tidak percaya diri (“still not confident”). If you mean “not very/insufficiently confident,” use kurang: … kurang percaya diri. To remove the “remain” idea, just say … tidak percaya diri without tetap.

Can I mention what she studied?

Yes. Add the subject: Setelah belajar matematika seharian, adik perempuan saya tetap percaya diri. With a specific object and a slightly more formal tone: Setelah mempelajari matematika seharian, … You can also add more detail: … belajar untuk ujian seharian …

Are there other natural ways to say the whole sentence?

Yes, for example:

Setelah seharian belajar, adikku tetap percaya diri.
Usai belajar seharian, adik perempuanku tetap percaya diri.
To highlight contrast: Meskipun sudah belajar seharian, adik perempuan saya tetap percaya diri.