Learn Hardcore Indonesian: Dia mengisi ulang pulsa telepon sebelum berangkat. - He/She tops up the phone credit before departing.

Dia is gender-neutral and can mean either “he” or “she.” Indonesian third-person singular pronouns don’t mark gender. For a respectful “he/she,” you can use beliau. Another written/formal option is ia (often used as a subject in narratives), but dia is the all-purpose everyday form.

Can I omit dia in this sentence?

In careful/standard Indonesian, keep dia in the main clause: Dia mengisi ulang …
You can omit the subject in the time clause if it’s the same as the main subject: Sebelum berangkat, dia mengisi ulang …
In casual speech, people sometimes drop dia if it’s obvious from context: Sebelum berangkat, mengisi ulang pulsa telepon dulu. (Very conversational.)

What does mengisi ulang literally mean?

Literally “to fill again” or “to refill.”

meng- + isi = mengisi “to fill”
ulang = “again”
Together: mengisi ulang = “to refill/recharge/top up.” With pulsa, it means “to top up phone credit.”

Could I just say mengisi pulsa or beli pulsa instead of mengisi ulang pulsa?

Yes. All are natural:

mengisi pulsa = top up credit
mengisi ulang pulsa = top up credit (emphasizes “again,” but that’s typically implied)
beli pulsa = buy credit
Colloquial speech often uses isi pulsa, ngisi pulsa, or even the loan top up pulsa.

Is mengisi ulang the same as “charging the phone battery”?

No. Don’t mix up credit top-ups with battery charging:

Credit top-up: (meng)isi (ulang) pulsa, beli pulsa
Battery charging: mengisi daya (baterai) (formal) or very commonly ngecas HP (casual)

What exactly is pulsa telepon?

It’s prepaid phone credit (airtime) used for calls/SMS and often to buy data packages. You’ll hear just pulsa in daily conversation. Saying pulsa telepon clarifies it’s phone credit (as opposed to, say, pulsa listrik for prepaid electricity).

Do I need the word telepon? Can I say pulsa HP?

You can just say pulsa if the context is obvious. Many people say pulsa HP (“HP” = handphone, i.e., mobile). Other common words for “phone” are ponsel (formal) and telepon; colloquially you’ll also see the spelling telpon.

How does sebelum work here? Why is there no subject after it?

Sebelum introduces a time clause meaning “before.” If the subject of the subordinate clause is the same as the main clause, it’s often omitted: Sebelum berangkat, dia … If the subject is different, include it: Dia mengisi ulang pulsa telepon sebelum mereka/Andi berangkat.
You can place the time clause first or last:

Sebelum berangkat, dia mengisi ulang …
Dia mengisi ulang … sebelum berangkat.
A comma after a fronted time clause is common but not mandatory.

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

Indonesian doesn’t mark tense on verbs. Time is inferred from context or shown with time words:

Past: tadi, kemarin, sudah (already) → Dia sudah mengisi ulang …
Future: nanti, besok, akan → Dia akan mengisi ulang …
Habitual: add adverbs like biasanya (“usually”)

What’s the difference between berangkat and pergi?

Both mean “to leave/go,” but:

berangkat = depart/set off (often scheduled or from a specific starting point; neutral-formal)
pergi = go/leave (broader, very common)
Here, sebelum berangkat sounds natural for “before leaving (to depart).”

Is it okay to say Dia isi ulang pulsa telepon… without the prefix?

In standard Indonesian with an actor subject, you’d use the active prefix: Dia mengisi ulang…
In everyday colloquial speech (especially Jakarta Indonesian), dropping the prefix is common: Dia isi ulang pulsa… Both are widely understood; choose based on formality.

How would I mark possession, like “his/her phone credit”?

Attach -nya to the possessed noun:

Dia mengisi ulang pulsa teleponnya. = He/she topped up his/her phone’s credit.
Note: -nya refers to someone already known in context; it could mean “his,” “her,” or “its,” depending on the discourse.

How do I say this in the passive voice?

Passive with di- focuses on the object:

Pulsa telepon (dia)-nya diisi ulang sebelum berangkat. (You can add oleh dia for clarity, but it’s usually omitted.) Colloquial short passive: Pulsa teleponnya diisi ulang…

Is isi ulang a fixed expression? Can it be a noun?

Yes. As a verb phrase: mengisi ulang (“to refill/top up”). As a noun phrase: isi ulang (“a refill/top-up”).

Verb: Dia mengisi ulang pulsa.
Noun: Saya mau isi ulang pulsa. (“I want a top-up.”) No hyphen is needed: write isi ulang, not “isi-ulang.”

What’s the difference between pulsa, kuota, and paket data?

pulsa: general prepaid credit (for calls/SMS, and to buy data packages)
kuota (data): a data allowance (MB/GB)
paket data: a data package/plan you purchase (with certain kuota and validity)

Any common add-ons I might hear with this sentence?

Yes, dulu (“first, beforehand”) is very common in speech:

Dia mengisi ulang pulsa telepon dulu sebelum berangkat. This emphasizes doing the top-up before the next action.

Is the spelling telepon or telpon? How do I pronounce it?

Standard spelling is telepon. You’ll often see telpon informally. Pronunciation varies regionally; a clear three-syllable te-le-pon is fine. Indonesian stress is light and not strongly contrastive.

Could I replace telepon with a more natural everyday word?

Yes:

HP (very common colloquial): pulsa HP
ponsel (formal): pulsa ponsel
smartphone is also understood, but HP is the go-to in daily speech.