Learn Hardcore Malay: Saya menabung di akaun simpanan supaya ada wang kecemasan. - I save in a savings account so that there is emergency money.

It almost always refers to saving money, usually in a bank or in some kind of savings container.
The base noun is tabung = a container for money (like a piggy bank).
Compared with English, menabung is closer to “to save up” than just “to save” in general.

You would not use menabung for saving a file on a computer or saving someone’s life; those use different verbs.

Why doesn’t the sentence say “menabung wang” or “menabung duit”? Where is the object?

In Malay, when the context is clear, the object “money” is often left out because menabung already strongly implies saving money.

So these are all natural:

Saya menabung. – I save (money).
Saya menabung di akaun simpanan. – I save (money) in a savings account.
Saya menabung duit / wang di akaun simpanan. – I save money in a savings account.

Adding duit or wang is correct but not necessary. Native speakers routinely omit it.

What is the difference between wang and duit? Why use wang kecemasan here?

Both refer to money, but the register is different:

wang – more formal / written; used in official documents, banking, news.
duit – more informal / everyday speech.

In speech, many people would naturally say:

… supaya ada duit kecemasan.

In a written example (like in a textbook or bank brochure), wang kecemasan sounds more appropriate and formal.

Why is it di akaun simpanan and not dalam akaun simpanan or ke akaun simpanan?

All three words exist but they’re used differently:

di = at / in (location marker, neutral and very common)
- di akaun simpanan focuses on the location of the savings (in the account).
dalam = inside (more physical/“inside-ness”)
- dalam akaun simpanan is also grammatical and understandable, but sounds slightly less natural for this banking context; di is preferred.
ke = to / towards (direction)
- ke akaun simpanan would mean “to the savings account” (direction of movement), and you would normally need a verb that shows transfer, e.g.
  - Saya memindahkan duit ke akaun simpanan. – I transfer money to the savings account.

So for a simple “I save (money) in a savings account”, di is the most natural.

What does akaun simpanan literally mean, and why is the noun order like that?

Akaun simpanan is literally “savings account”:

akaun – account
simpanan – savings / something stored away

Malay typically uses “main noun + describing noun” (a noun phrase), which you can think of as similar to “account (of) savings”:

akaun simpanan – savings account
kad kredit – credit card
buku teks – textbook

You cannot reverse it to simpanan akaun here; that would sound wrong or at least unnatural in this meaning.

What does supaya mean, and how is it different from untuk or agar?

Supaya introduces a purpose/result clause and is roughly “so that / in order that”.

Saya menabung … supaya ada wang kecemasan.
– I save in a savings account so that there is emergency money.

Differences:

supaya – “so that”, followed by a full clause (with a verb):
- supaya ada wang kecemasan (so that there is emergency money)
untuk – “for / in order to”, followed by a noun or verb phrase:
- untuk wang kecemasan – for emergency money
- untuk menabung – in order to save

Agar is very similar to supaya, slightly more formal/literary, often interchangeable:

… agar ada wang kecemasan. – also “so that there is emergency money”.

In everyday modern usage, supaya is more common than agar.

Why does it say “supaya ada wang kecemasan” and not “supaya saya ada wang kecemasan”? Isn’t the subject missing?

In Malay, if the subject is obvious from context, it can be left out.

Here, “saya” is already used at the start (Saya menabung…), so the listener understands the emergency money belongs to me.

These are all acceptable:

supaya ada wang kecemasan. – so that (there) is emergency money.
supaya saya ada wang kecemasan. – so that I have emergency money.

The first sounds a bit more general/impersonal; the second explicitly mentions saya and slightly emphasizes my having the money. Both are correct.

How is kecemasan working here? Why is it wang kecemasan and not something like kecemasan wang?

Kecemasan means “emergency” (noun).

In Malay noun phrases, the typical order is:

main noun + describing word/phrase

So:

wang kecemasan – emergency money (literally: money [for] emergency).
bantuan kecemasan – emergency aid.
pintu kecemasan – emergency exit.

You would not say kecemasan wang for “emergency money”; that order doesn’t work.

How do we know the tense here? Does menabung mean present tense, past, or future?

Menabung itself has no tense marking. Malay verbs normally do not change form for tense.

The sentence can mean:

I save money in a savings account so that there is emergency money. (habitual present)
I am saving … (present, from context)
I will save … (future, from context, or with an extra word like akan).

If you need to make the time explicit, you add time expressions or markers:

Saya akan menabung… – I will save…
Saya sedang menabung… – I am (currently) saving…
Dulu saya menabung… – I used to save / I saved before…

Is this sentence formal or informal? How would people say this casually?

The given sentence is neutral, slightly leaning formal because of wang and the complete structure.

In casual spoken Malay, you might hear:

Saya simpan duit dalam akaun simpanan, supaya ada duit kecemasan.
Saya menabung dalam akaun simpanan, supaya ada duit kecemasan.

Changes in casual speech:

duit instead of wang
dalam instead of di is OK in speech, though di is still common
sometimes even dropping saya if context is clear:
- Menabung dalam akaun simpanan supaya ada duit kecemasan.

What is the difference between menabung and menyimpan duit or simpan duit?

They overlap but have slightly different feel:

menabung – specifically saving money, usually with the idea of building up savings over time (bank, piggy bank, etc.).
menyimpan duit / simpan duit – literally “to keep money”; can mean “to save”, but also “to keep/hold money”, not necessarily in an account.

Examples:

Saya menabung di bank. – I save (money) in the bank.
Saya simpan duit di rumah. – I keep my money at home.
Saya simpan duit untuk bercuti. – I’m saving/keeping money for a holiday.

In your sentence, menabung is very natural because we’re talking about a savings account.

Could you drop “di akaun simpanan”? What would “Saya menabung supaya ada wang kecemasan” mean?

Yes, you can drop it. Then it simply means:

Saya menabung supaya ada wang kecemasan.
– I save (money) so that there is emergency money.

This is more general: you save money somehow (in any way, not specifically in a savings account).

By adding di akaun simpanan, you specify how/where you save:

Saya menabung di akaun simpanan… – I save (money) in a savings account…