Learn Hardcore Indonesian: Dia pulang lebih awal karena urusan keluarga. - He/She goes home earlier because of a family matter.

ia: more formal/literary (often in writing).
beliau: respectful form for elders or important people. Note: dia is third person; don’t use it to address someone directly.

What’s the nuance of pulang compared with kembali, balik, and pergi?

pulang: go/come home (to one’s base/origin). You can add a destination (pulang ke Surabaya/rumah/kos). Pulang ke rumah is often redundant but acceptable.
kembali: return/come back to a previous place or state (not necessarily home).
balik: informal for “go/come back.”
pergi: go/leave (neutral). If someone left an event early but didn’t go home, say pergi lebih awal or keluar lebih awal, not pulang. Caution: berpulang can mean “to pass away” (euphemism), so don’t use it for everyday “go home.”

Is the word order pulang lebih awal fixed? Can I say lebih awal pulang?

Use pulang lebih awal. Placing lebih awal before the verb (lebih awal pulang) is awkward. If you add a destination, it comes before lebih awal: Dia pulang ke kos lebih awal.

Does lebih make a comparative? What’s the difference between lebih awal and lebih cepat?

Yes, lebih + adjective/adverb makes a comparative.

lebih awal: earlier in time/schedule.
lebih cepat: faster speed/finishing sooner (may imply doing the action more quickly). Examples:
Kereta berangkat lebih awal.
Dia selesai lebih cepat daripada saya.

What tense is the sentence? How do I show past or future?

Indonesian has no verb tenses; time comes from context or time words:

Past/recent: tadi, kemarin, barusan.
Completed: sudah, telah (formal).
Future: akan, nanti. Examples: Tadi dia pulang lebih awal, Dia akan pulang lebih awal, Dia sudah pulang lebih awal.

Can I put the reason first: Karena urusan keluarga, dia pulang lebih awal?

Yes. Fronting the reason is natural. Use a comma when the reason comes first: Karena urusan keluarga, dia pulang lebih awal. When the reason follows, a comma is usually unnecessary: Dia pulang lebih awal karena urusan keluarga.

Do I need ada before urusan keluarga, like karena ada urusan keluarga?

Both are correct:

karena urusan keluarga: states the cause plainly.
karena ada urusan keluarga: emphasizes the existence of some family matter; common in speech. Meaning difference is minimal; ada adds an “there is/was” feel.

What exactly does urusan keluarga mean? How is it different from keperluan keluarga, masalah keluarga, or acara keluarga?

urusan keluarga: family matters/affairs (neutral: errands, obligations, paperwork).
keperluan keluarga: family needs/requirements (purpose-oriented).
masalah keluarga: family problems (implies difficulty).
acara keluarga: family event/occasion (gathering, ceremony). Pick based on the nuance you want.

Should I mark possession, like keluarganya, to mean his/her family?

Not necessary. urusan keluarga is typically understood as the subject’s own family. Use possessives for clarity/emphasis:

urusan keluarganya (his/her family matters)
urusan keluarga saya/kami (my/our family matters)
urusan keluarga dia (informal, spoken)

Can I use sebab, gara-gara, or soalnya instead of karena?

Yes, with register differences:

sebab: formal/literary; similar to karena.
gara-gara: informal; often carries a slightly negative/blamey tone.
soalnya: very colloquial; usually starts a new clause/sentence. Examples:
Dia pulang lebih awal sebab urusan keluarga.
Dia pulang lebih awal gara-gara urusan keluarga.
Dia pulang lebih awal. Soalnya ada urusan keluarga.

Is pulang transitive? What about memulangkan?

pulang is intransitive (no direct object). You can’t say Dia pulang saya.
memulangkan is transitive: to send/return someone or something home/back. Examples:
Bos memulangkan karyawan itu lebih awal.
Polisi memulangkan anak itu ke orang tuanya.

How do I say too early?

Neutral: terlalu awal.
Colloquial: kepagian (especially for arriving/doing something earlier than ideal). Examples: Dia datang terlalu awal, Aku kepagian, kantornya belum buka.

Is there a difference between lebih awal and lebih dulu/lebih dahulu or duluan?

lebih awal: earlier in time (neutral).
lebih dulu/lebih dahulu: earlier/before others; emphasizes sequence/order.
duluan: colloquial “before you/the others.” Examples: Saya pulang lebih awal hari ini, Saya pulang lebih dulu, ya, Saya duluan, ya.

If the person left the event early but not to go home, what should I say?

Use a general “leave” verb:

Dia pergi lebih awal.
Dia keluar lebih awal dari rapat.
Dia meninggalkan acara itu lebih awal. Reserve pulang for going home/base.

Can I omit dia if it’s clear from context?

Yes, Indonesian often drops subjects when context is clear, especially in replies. In a full standalone sentence, keep dia. In conversation, you might hear simply: Pulang lebih awal karena urusan keluarga.