Learn Hardcore Indonesian: Adik perempuan saya membuat kue cokelat untuk ulang tahun temannya. - My younger sister makes a chocolate cake for her friend’s birthday.

Adik = younger sibling
perempuan = female, woman (here: indicating that the sibling is female)
saya = my / I (here: my)
→ adik perempuan saya = my younger sister (literally: younger sibling female my)
membuat = to make / made
(Indonesian verbs don’t change form for tense; membuat can mean make / makes / made depending on context.)
kue = cake
cokelat = chocolate
→ kue cokelat = chocolate cake (literally: cake chocolate)
untuk = for
ulang tahun = birthday (literally: repeat year)
temannya = his/her/their friend; the friend
- teman = friend
- -nya = his / her / its / their OR “the” (definite) depending on context

Full natural translation: My younger sister made a chocolate cake for her friend’s birthday.

Why is it adik perempuan saya and not saya adik perempuan for “my younger sister”?

In Indonesian, the usual pattern for possession is:

possessed noun + possessor

So you say:

adik perempuan saya = my younger sister
rumah saya = my house
buku dia = his/her book

Putting saya first (saya adik perempuan) is not how possession is expressed; that would sound ungrammatical or at least very odd.

You can also attach -ku to the noun:

adik perempuanku = my younger sister (more informal / personal in many contexts)

Do I need the word perempuan? Can I just say adik saya?

You don’t need perempuan, but it changes how specific you are:

adik saya = my younger sibling (gender not specified)
adik perempuan saya = my younger sister
adik laki-laki saya = my younger brother

If the gender is already clear from context, people often just say adik saya. If you want to explicitly say “younger sister,” adik perempuan is the standard, clear way.

How do we know membuat means “made” (past) here, and not “makes” or “is making”?

Indonesian verbs do not change form for tense. Membuat by itself is neutral:

Dia membuat kue.
Can mean:
- He/She makes cakes (habitually).
- He/She is making a cake.
- He/She made a cake.

You infer the time from context, time expressions, or surrounding sentences. In your sentence, English speakers naturally choose made because it’s about a specific birthday event, but Indonesian doesn’t mark the past explicitly.

If you wanted to be very clear about time, you might add an adverb:

Kemarin adik perempuan saya membuat kue cokelat…
= Yesterday my younger sister made a chocolate cake…

Why is it kue cokelat and not cokelat kue for “chocolate cake”?

In Indonesian, the typical order is:

main noun + describing word

So:

kue cokelat = chocolate cake (cake of chocolate flavour/type)
baju merah = red shirt
mobil baru = new car

Putting cokelat before kue (cokelat kue) is not how this meaning is expressed; it would sound wrong to native speakers.

Note: kue cokelat usually means a cake flavoured with or made of chocolate, not just a cake that happens to be brown.

What is the difference between untuk and other words that can mean “for”, like buat or kepada?

In this sentence, untuk means for (the purpose of / intended for):

kue cokelat untuk ulang tahun temannya
= a chocolate cake for her friend’s birthday

Common contrasts:

untuk
- more neutral, standard
- used for purposes, beneficiaries, goals
- Hadiah ini untuk kamu. = This gift is for you.
buat
- more informal / colloquial
- often interchangeable with untuk in casual speech
- Kue ini buat ulang tahun dia. = This cake is for his/her birthday.
kepada
- “to” in the sense of directing something to someone (often more formal, like to a recipient)
- Dia memberi kue kepada temannya. = He/She gave a cake to his/her friend.

In your sentence, untuk is the normal, standard choice.

What does ulang tahun literally mean, and is it always “birthday”?

Literally:

ulang = repeat
tahun = year
→ ulang tahun = repeated year

Functionally, ulang tahun means birthday, and that’s how it’s usually used:

Selamat ulang tahun! = Happy birthday!

You might also see:

hari ulang tahun = birthday (literally: birthday day)
Often shortened in speech to just ulang tahun.

Context normally makes it clear we’re talking about a birthday, not some other kind of “yearly repetition.”

What exactly does temannya mean, and whose friend is it?

Temannya is made of:

teman = friend
-nya = his / her / its / their OR “the (specific)”

So temannya can mean:

his friend / her friend / their friend
or the friend (definite, known from context)

In your sentence:

Adik perempuan saya membuat kue cokelat untuk ulang tahun temannya.

Most natural interpretation is:

My younger sister made a chocolate cake for her friend’s birthday.

By default, -nya here is understood to refer back to the subject, adik perempuan saya. If you wanted to say clearly that it’s my friend instead, you would usually say:

… untuk ulang tahun teman saya. = …for my friend’s birthday.

Can temannya be plural, like “her friends’ birthday”?

-nya by itself does not mark singular or plural. It’s neutral for number. But in this context:

ulang tahun temannya is naturally understood as the birthday of one friend.

To clearly make it plural, Indonesian typically uses reduplication:

teman-temannya = his/her/their friends
ulang tahun teman-temannya = (one) birthday celebration for several friends, or the birthdays of several friends (context clarifies)

So in your exact sentence, stick with the singular interpretation unless something in the wider context says otherwise.

Could I say adik saya yang perempuan instead of adik perempuan saya?

You can, but the nuance is slightly different:

adik perempuan saya
= my younger sister (a fixed, standard noun phrase)
adik saya yang perempuan
= my younger sibling who is female

The second form sounds a bit more like you’re distinguishing between multiple younger siblings, e.g., “Among my younger siblings, the one who is female…”. It’s grammatical, but adik perempuan saya is the usual, simpler way to say “my younger sister.”

Is it possible to drop saya and just say Adik perempuan membuat kue cokelat…?

You generally need some indication of whose adik it is, unless the context is extremely clear.

Adik perempuan saya… = my younger sister
Adik perempuanmu… = your younger sister
Adik perempuannya… = his/her younger sister

If you say just Adik perempuan membuat kue…, it sounds incomplete or odd, like saying “Younger sister made a cake…” without saying whose sister. Native speakers very rarely talk about adik without some possessor, unless it’s in a very specific, understood family context (and even then they often still use a possessor).

Can I use aku instead of saya in this sentence?

You don’t replace saya directly here, because saya is attached to the noun phrase as a possessive.

Options:

Adik perempuan saya membuat kue cokelat…
(neutral / polite)
Adik perempuan aku membuat kue cokelat…
(informal; mixing adik perempuan with aku is possible in casual contexts, but a bit less common than using possessive suffix)
Adik perempuanku membuat kue cokelat…
(informal, very natural; possessive suffix -ku corresponds to aku)

So yes, you can express the same idea in a way that matches aku, but you normally do it by using -ku: adik perempuanku.