Setiap akhir bulan, saya membuka celengan itu untuk menghitung tabungan tambahan.

In Indonesian, time expressions often appear directly in the sentence without a preposition.

• Setiap akhir bulan = every end of the month / at the end of every month
• You do not need pada here.

So:

• Setiap akhir bulan, saya membuka... is completely natural.
• Pada setiap akhir bulan... is possible, but it sounds more formal and less common in everyday speech.

Indonesian often places time expressions at the beginning of a sentence to set the context, just like Every month, I... in English.

It specifically means at the end of every month.

Breakdown:

• setiap = every
• akhir = end
• bulan = month

So this is more specific than just setiap bulan, which means every month in a general sense.

Compare:

• Setiap bulan = every month
• Setiap akhir bulan = at the end of every month

Membuka is the active verb form built from the root buka (to open).

• buka = root word
• membuka = to open / opens / am opening, depending on context

The prefix meN- often marks an active verb in standard Indonesian.

So:

• saya membuka celengan itu = I open that piggy bank
• Using just saya buka celengan itu is also possible in casual speech, but membuka sounds more standard and complete.

For the same reason as membuka: menghitung is the active verb form of hitung (count).

• hitung = root
• menghitung = to count

In standard Indonesian, verbs in full sentences often take this active prefix.

So:

• untuk menghitung = to count
• untuk hitung may appear in casual speech, but untuk menghitung is the standard form.

Celengan usually means a container used to save coins or money, often translated as:

• piggy bank
• money box
• coin bank

It does not have to literally be pig-shaped. In Indonesian, celengan refers to the object used for saving loose money, whatever its shape is.

So membuka celengan itu means opening the savings container/piggy bank.

In Indonesian, demonstratives like ini (this) and itu (that/the) usually come after the noun.

So:

• celengan itu = that piggy bank / the piggy bank
• buku ini = this book
• rumah itu = that house

This is the normal Indonesian word order.

English: that piggy bank
Indonesian: celengan itu

It can function like both, depending on context.

In this sentence, celengan itu could mean:

• that piggy bank if you are pointing to a specific one
• the piggy bank if both speaker and listener already know which one it is

Indonesian does not have articles like the and a/an, so words like itu often help show that something is specific or already known.

Untuk here means to or in order to and introduces the purpose of the action.

So:

• membuka celengan itu untuk menghitung tabungan tambahan = open the piggy bank to count the extra savings

It connects the first action with its purpose:

• action: membuka celengan itu
• purpose: untuk menghitung tabungan tambahan

It means something like:

• additional savings
• extra savings
• the extra money saved

Breakdown:

• tabungan = savings / money that has been saved
• tambahan = additional / extra

Together, tabungan tambahan refers to savings that are extra or added on top of something else.

Depending on context, it could mean:

• extra money saved in the piggy bank
• savings in addition to regular savings
• a little additional amount accumulated over time

In Indonesian, modifiers often come after the noun.

So:

• tabungan tambahan = additional savings
• uang tambahan = extra money
• biaya tambahan = additional cost

This is the normal pattern: noun + modifier.

While tambahan tabungan might appear in some contexts, it would feel less like a simple noun phrase and more like an addition to savings. For this sentence, tabungan tambahan is the natural choice.

The subject is understood to be the same as the main clause: saya.

So the sentence means:

• I open the piggy bank in order to count the extra savings.

Indonesian often does not repeat the subject when it is already clear from context.

You do not need to say:

• ...untuk saya menghitung...

That version is possible in some cases, but here it sounds unnecessary and less natural.

Indonesian does not mark plurality the same way English does.

• tabungan can already mean savings
• You do not need a plural form for it

In English, savings is grammatically plural-looking, but in Indonesian tabungan works as a normal noun without needing reduplication or another plural marker.

Plurality in Indonesian is often left to context unless it needs to be emphasized.

The sentence can be rearranged somewhat, but the original order is very natural.

Original:

• Setiap akhir bulan, saya membuka celengan itu untuk menghitung tabungan tambahan.

You could also say:

• Saya membuka celengan itu setiap akhir bulan untuk menghitung tabungan tambahan.

Both are correct.

The difference is mainly focus:

• Setiap akhir bulan, ... emphasizes the time first
• Saya membuka..., setiap akhir bulan... emphasizes the subject/action first

Putting the time expression first is very common in Indonesian.

It is mostly neutral to standard Indonesian.

Why?

• saya is neutral/polite for I
• membuka and menghitung use standard verb forms
• the whole sentence sounds natural in writing and careful speech

A more casual spoken version might be:

• Setiap akhir bulan, saya buka celengan itu buat hitung tabungan tambahan.

Changes:

• membuka → buka
• untuk → buat
• menghitung → hitung

That version is more conversational, while the original is a good standard model for learners.