Saya mengisi ulang kartu bus tadi pagi.

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Breakdown of Saya mengisi ulang kartu bus tadi pagi.

• tadi pagi: this morning
• mengisi ulang: to top up
• kartu bus: the bus card

Questions & Answers about Saya mengisi ulang kartu bus tadi pagi.

What does mengisi ulang literally mean and how is it formed?

Breakdown:

• isi = fill, contents
• meng- + isi → mengisi = to fill (meN- prefix; with a vowel-initial root it becomes meng-)
• ulang = again/repeat So mengisi ulang is “to fill again” → “to refill/reload,” the standard verb for topping up a card, phone credit, etc.

Can I just say mengisi without ulang?

If you say mengisi kartu bus, it sounds incomplete/odd. For topping up balance, use:

• mengisi ulang (kartu bus), or
• mengisi saldo kartu bus / menambah saldo. Mengisi alone is fine if you name what you fill (e.g., mengisi formulir, mengisi saldo).

Is isi ulang a noun too, or only a verb?

Both:

• Noun: isi ulang = a refill/top-up (e.g., tempat isi ulang air “water refill station”).
• Verb (informal/neutral): bare isi ulang: Saya isi ulang kartu bus… In formal writing, prefer mengisi ulang.

Why not say mengisi lagi instead of mengisi ulang?