Sebelum membayar di supermarket, saya mengecek saldo dompet digital di telepon saya.

In Indonesian, if the subject is obvious from context, it is often left out in a subordinate clause.

So in Sebelum membayar di supermarket, saya mengecek ..., the understood subject of membayar is the same saya from the main clause.

A fuller version, Sebelum saya membayar di supermarket, saya mengecek ..., is also correct, but the original is more natural and less repetitive.

Sebelum means before.

It can be followed by:

• a verb phrase: sebelum membayar = before paying
• a clause: sebelum saya membayar = before I pay

In your sentence, sebelum membayar di supermarket works like before paying at the supermarket.

Bayar is the root word, meaning pay or payment depending on context.

Membayar is the active verb form made with the meN- prefix, and it means to pay.

So:

• bayar = root/base form
• membayar = active verb, to pay

In full sentences, membayar is usually the expected form:

• Saya membayar = I pay / I am paying

In casual speech, Indonesians sometimes say bayar without the prefix, but membayar is more standard.

Mengecek means to check.

It comes from cek, which is a borrowed word from English check, plus the Indonesian active prefix meN-.

So:

• cek = check
• mengecek = to check

This is very common in everyday Indonesian. A more formal or more purely Indonesian alternative is memeriksa.

Compare:

• Saya mengecek saldo = everyday, natural
• Saya memeriksa saldo = also correct, a bit more formal

This is because of how the meN- prefix works with short root words, especially one-syllable roots.

For short roots like cek, Indonesian often uses menge-:

• cek → mengecek

So this is a normal pattern, not an irregular form you just have to memorize separately.

Saldo means balance, especially a financial balance.

Common examples:

• saldo rekening = account balance
• saldo dompet digital = e-wallet balance

So mengecek saldo means to check the balance.

Yes. Dompet digital is a normal way to say digital wallet or e-wallet.

Literally:

• dompet = wallet
• digital = digital

It refers to apps or services used for storing money electronically, such as e-wallet payment apps.

You may also hear:

• e-wallet
• dompet elektronik

But dompet digital is very natural and common.

Because the sentence has two different location phrases:

• di supermarket = at/in the supermarket
• di telepon saya = on my phone

Here, di is a preposition meaning in / at / on, and it is written separately from the following word.

This is different from the passive prefix di-, which is attached to a verb, for example:

• dibayar = is paid
• dicek = is checked

So:

• di supermarket = preposition, separate
• dibayar = passive prefix, attached

Yes. Indonesian often uses di for locations in a broad sense, including devices, screens, apps, and platforms.

So di telepon saya naturally means on my phone.

Other examples:

• di komputer saya = on my computer
• di aplikasi itu = in/on that app
• di internet = on the internet

English makes finer distinctions between in, on, and at, but Indonesian di covers all of those depending on context.

It is understandable and correct, but in modern everyday Indonesian, many speakers would more naturally say:

• ponsel saya
• HP saya
• handphone saya

So your sentence is fine, but a very natural everyday version might be: Sebelum membayar di supermarket, saya mengecek saldo dompet digital di HP saya.

That said, telepon saya is still perfectly clear.

In di telepon saya, the saya belongs to telepon.

So it means on my phone.

The structure is:

• telepon saya = my phone

It does not mean my digital wallet balance. If you wanted to say my digital wallet balance, you would say:

• saldo dompet digital saya

So word placement matters:

• saldo dompet digital di telepon saya = the balance of the digital wallet, checked on my phone
• saldo dompet digital saya = my digital wallet balance

Not really in normal context. Indonesian speakers will understand di telepon saya as describing where the checking happens, or where the app is being used.

Because dompet digital is already something electronic, the phrase naturally reads as: I check the balance using/on my phone.

If you want to make that relationship even clearer, you could say:

• melalui telepon saya = through my phone
• di aplikasi dompet digital di telepon saya = in the digital wallet app on my phone

But the original sentence is already natural.

Because of the word order and meaning.

Sebelum membayar di supermarket means before paying at the supermarket. The phrase di supermarket goes naturally with membayar.

Then the second location phrase, di telepon saya, goes with mengecek.

So the sentence breaks down like this:

• Sebelum membayar di supermarket = Before paying at the supermarket
• saya mengecek saldo dompet digital di telepon saya = I check the balance of the digital wallet on my phone

Yes. Indonesian verbs do not change form for tense the way English verbs do.

So saya mengecek can mean:

• I check
• I am checking
• I checked

The exact time usually comes from context, time words, or the wider situation.

In your sentence, sebelum already gives a time relationship, so the meaning is clear even without verb tense marking.

Yes, but that means something slightly different.

• Saya mengecek saldo dompet digital saya = I check my digital wallet balance
• Saya mengecek saldo dompet digital di telepon saya = I check the digital wallet balance on my phone

The first focuses on whose wallet it is. The second focuses on where/how you are checking it.

You can also combine both ideas: Saya mengecek saldo dompet digital saya di telepon saya.

The sentence is natural and correct. But depending on context, many speakers might choose slightly more everyday wording, for example:

• Sebelum bayar di supermarket, saya cek saldo dompet digital di HP saya.
• Sebelum membayar di supermarket, saya memeriksa saldo dompet digital di ponsel saya.

Differences:

• bayar / cek / HP = more casual, everyday
• membayar / memeriksa / ponsel = more standard or formal

Your original sentence sits comfortably in the middle: clear, natural, and standard enough for learners.