Learn Hardcore Indonesian: Saya memakai kalkulator ketika menghitung angka di kolom terakhir supaya tidak salah. - I use a calculator when calculating the numbers in the last column so that I do not make mistakes.

saya: neutral, polite, suitable for most situations (talking to strangers, at work, in writing, etc.).
aku: more informal/intimate; used with close friends, family, or in casual speech, songs, etc.

In this sentence, you can say:

Aku memakai kalkulator ketika menghitung angka di kolom terakhir supaya tidak salah.

That just makes the tone more casual. Grammatically, both are correct.

Why memakai and not just pakai or menggunakan? Are they different?

All three are possible, but they have slightly different flavors:

memakai = to wear / to use
- Here it means to use.
- Slightly more neutral and common in many contexts.
pakai = base form of memakai, also very common in speech.
- In everyday Indonesian, people often say pakai kalkulator instead of memakai kalkulator.
- Sounds a bit more casual.
menggunakan = to use, to utilize
- Slightly more formal or “bookish”.
- You could say Saya menggunakan kalkulator ..., and it would sound a bit more formal.

All are grammatically correct in this sentence:

Saya memakai kalkulator ...
Saya pakai kalkulator ... (more casual)
Saya menggunakan kalkulator ... (more formal)

What does the me- prefix in memakai and menghitung do?

The meN- prefix (often written me- for simplicity) is a very common verb-forming prefix in Indonesian. It:

Turns a base word (often a verb or noun) into an active transitive verb (a verb that usually takes an object).
Changes form depending on the first consonant of the root:
- pakai → memakai
- hitung → menghitung

So in this sentence:

memakai = to use (something)
menghitung = to calculate / to count (something)

In dictionaries, you often see the base forms (pakai, hitung), but in sentences, you frequently use the meN- forms when the verb has an object.

Why is it menghitung and not just hitung?

You could technically say both, but they differ in style and function:

menghitung angka is the standard full verb phrase:
- menghitung (active verb) + angka (object)
- This is the most natural in neutral/formal sentences.
hitung angka:
- Often sounds like an imperative (a command: “count the numbers”).
- The bare root hitung is also used in some fixed phrases or titles.

In a narrative statement like this, menghitung angka is the default, natural choice:

ketika menghitung angka = when (I am) calculating the numbers

Why is it ketika and not saat or waktu? Are they interchangeable?

ketika, saat, and waktu can all mean when in many contexts, but there are nuances:

ketika:
- Slightly formal/neutral.
- Very common in writing and careful speech.
- Fits perfectly here: ketika menghitung angka ...
saat:
- Also common, maybe feels a bit more “literary” or factual in some contexts.
- You could say: Saya memakai kalkulator saat menghitung angka di kolom terakhir ...
waktu:
- Literally means time, but in colloquial Indonesian often used as when.
- More casual: Saya memakai kalkulator waktu menghitung angka ...

Here, ketika, saat, and waktu are all acceptable. The original ketika sounds neutral and slightly more standard.

Why does ketika menghitung angka ... not repeat saya? Shouldn’t it be ketika saya menghitung angka ...?

Both forms are correct:

ketika menghitung angka di kolom terakhir ...
ketika saya menghitung angka di kolom terakhir ...

In Indonesian, if the subject is the same as in the main clause (saya here), it is often dropped in the subordinate clause to avoid repetition, especially in speech and informal/neutral writing.

Meaning-wise, both are the same:

Saya memakai kalkulator ketika menghitung angka ...
Saya memakai kalkulator ketika saya menghitung angka ...

The first just sounds smoother and more natural.

What’s the difference between angka and nomor? Both translate as “number”, right?

Yes, both can translate as number, but they are used differently:

angka:
- Digits, numerical figures, scores, statistics.
- Examples:
  - angka 5 (the digit 5)
  - angka kematian (death rate)
  - angka ujian (exam score)
nomor:
- Identification numbers, labels, positions.
- Examples:
  - nomor telepon (phone number)
  - nomor rumah (house number)
  - nomor punggung pemain (player’s jersey number)

In menghitung angka di kolom terakhir, angka is correct because you’re counting numeric values in a column (like in a table or spreadsheet), not ID numbers.

What does di kolom terakhir literally mean, and why is there no word for “the” before “last column”?

di kolom terakhir literally breaks down as:

di = in / at / on (location preposition)
kolom = column
terakhir = last / final

So di kolom terakhir = in the last column.

Indonesian does not use articles like the or a/an, so:

kolom terakhir can mean:
- last column
- the last column

The “the” is understood from context, not from a separate word.

Could I use pada kolom terakhir instead of di kolom terakhir?

Yes, but there is a nuance:

di kolom terakhir:
- Very natural and common in everyday speech and writing.
- di is the default preposition for location.
pada kolom terakhir:
- More formal, often seen in official documents, academic writing, instructions, etc.

In this sentence, di kolom terakhir is the most natural choice for general use.

What exactly does supaya mean, and how is it different from agar, biar, or jadi?

supaya introduces a purpose or goal, usually translated as so that / in order that.

In this sentence:

supaya tidak salah = so that (I) don’t make a mistake.

Close equivalents:

agar:
- Very close to supaya, slightly more formal/literary.
- ... agar tidak salah.
biar:
- More casual/colloquial.
- ... biar tidak salah.
jadi:
- Means so / as a result, but this is more about result, not purpose.
- You would not usually replace supaya with jadi here; it would change the meaning from “purpose” to “consequence”.

So:

supaya / agar / biar ⇒ purpose (so that)
jadi / sehingga ⇒ result (so / therefore)

Why is it tidak salah (“not wrong”) instead of something like benar (“correct”)?

Both ideas are possible, but Indonesian often uses tidak salah in this type of context:

supaya tidak salah = so that (I) don’t make a mistake / don’t get it wrong.

You could also say:

supaya benar = so that it is correct
supaya tidak salah hitung = so that I don’t miscalculate

salah is very commonly used for:

being wrong / a mistake / an error.

Saying tidak salah is a very natural, idiomatic way to express avoid making mistakes.

Is kalkulator singular or plural here? How do you say “calculators” in Indonesian?

Indonesian usually does not mark plural on nouns. kalkulator can mean calculator or calculators, depending on context.

In this sentence, context suggests a calculator (one device):

Saya memakai kalkulator ... = I use a calculator ...

If you really need to emphasize plural, you can:

Use reduplication: kalkulator-kalkulator (rare and sounds awkward here).
Add a number: tiga kalkulator (three calculators).
Use a phrase: beberapa kalkulator (several calculators).

But normally you just say kalkulator, and context tells you whether it’s singular or plural.

Shouldn’t it be ketika sedang menghitung to mean “when I am calculating”? Why is sedang missing?

sedang marks an ongoing action (similar to English -ing / “be doing”), but it is optional when the context already makes the time/aspect clear.

ketika menghitung angka already implies an action in progress (when (I am) calculating the numbers).
Adding sedang is possible but not necessary:
- ketika sedang menghitung angka di kolom terakhir ...

That version emphasizes the “in the middle of doing it” feel a bit more, but the original without sedang is completely natural and very common.

Could I change the word order to start with ketika? For example: Ketika menghitung angka di kolom terakhir, saya memakai kalkulator supaya tidak salah. Is that okay?

Yes, that is perfectly grammatical and natural. You can place the when-clause either before or after the main clause:

Saya memakai kalkulator ketika menghitung angka di kolom terakhir supaya tidak salah.
Ketika menghitung angka di kolom terakhir, saya memakai kalkulator supaya tidak salah.

Both mean the same thing. Starting with ketika slightly emphasizes the situation/time first, then the action.