Learn Hardcore Malay: Saya bimbang adik saya akan ponteng sekolah lagi. - I am worried my younger sibling will skip school again.

In this sentence, adik saya makes it explicit whose younger sibling it is.
If you were already talking about your sibling and everyone understood that, you might shorten it to adik in casual speech, but adik saya is the default, clear form.

Does adik mean “younger brother” or “younger sister”? How do I show the gender?

adik means younger sibling, without specifying gender.

To make it clear:

adik lelaki saya = my younger brother
adik perempuan saya = my younger sister

In many everyday situations, context or previous mention will tell you whether it’s a boy or a girl, so people often just say adik saya.

What exactly does bimbang mean, and how is it different from risau or takut?

All three are about negative feelings, but they’re used a bit differently:

bimbang – worried, anxious about something that might happen
- Saya bimbang keputusan peperiksaan.
risau – very close to bimbang, often a bit more informal/colloquial
- Saya risau dia tak sihat.
takut – afraid, scared
- Saya takut anjing.

In your sentence, saya bimbang … could almost always be replaced with saya risau … with the same meaning in everyday conversation. takut would sound more like “I’m scared that…”

What does akan do here? Is it like the English future “will”? Can it be left out?

Yes, akan is a future-time marker. It often corresponds to English “will” or “going to”.

adik saya akan ponteng sekolah
≈ my younger sibling will skip school

In everyday Malay, akan is often optional when the future is clear from context:

Adik saya ponteng sekolah lagi.
(Still usually understood as future, because of context and lagi = again.)

Using akan here makes the future aspect a bit clearer and slightly more formal/standard.

Why is akan before ponteng and not at the very beginning of the clause?

The usual word order for akan is:

subject + akan + verb (+ object)

So:

adik saya akan ponteng sekolah
(subject) (future marker) (verb) (object)

You wouldn’t normally say akan adik saya ponteng sekolah in standard Malay. akan attaches to the verb phrase, not to the whole clause like English “will” sometimes seems to.

Why is it just ponteng sekolah, not something like memonteng sekolah with a prefix?

ponteng is already a common verb meaning to skip / play truant, especially for school.

Malay has a meN- verb-forming prefix (like in membaca, menulis), but:

ponteng sekolah is a fixed, very common expression: to skip school
A form like memonteng is possible in theory but is rare/unnatural in this meaning

So you should treat ponteng sekolah as a set phrase: ponteng (to skip) + sekolah (school).

Is ponteng specifically about school, or can it mean skipping other things?

ponteng is most strongly associated with not attending something you’re supposed to attend, especially:

ponteng sekolah – skip school
ponteng kerja – skip work / play hooky from work
ponteng kelas – skip class

So it’s not only about school, but ponteng sekolah is the most common collocation learners meet first.

What does lagi mean at the end of the sentence? Why is it placed there?

Here, lagi means again.

ponteng sekolah lagi = skip school again

Common uses of lagi:

lagi = again
- Dia lewat lagi. – He’s late again.
lagi = more / another
- Saya mahu satu lagi. – I want one more.
lagi = still (in some constructions)
- Dia masih lagi tidur. – He’s still sleeping.

When lagi means again, it usually comes after the verb phrase, as in ponteng sekolah lagi.

Could I say Saya bimbang yang adik saya akan ponteng sekolah lagi or bahawa adik saya…? Is that more correct?

Yes, both are grammatically correct:

Saya bimbang yang adik saya akan ponteng sekolah lagi.
Saya bimbang bahawa adik saya akan ponteng sekolah lagi.

Points to note:

yang as a complementizer like “that” is colloquial/neutral.
bahawa is more formal/written, like “that” in careful English.

In everyday spoken Malay, the yang/bahawa is very often omitted, just like in the original sentence. So your original version is perfectly natural.

Is this sentence formal or informal? How would it sound in different registers?

Overall, it’s neutral–informal, suitable for everyday conversation.

bimbang – slightly formal/neutral word for “worried”, but very common
ponteng sekolah – quite colloquial/informal

More formal alternatives:

Saya bimbang adik saya tidak akan hadir ke sekolah lagi.
Saya khuatir adik saya akan tidak hadir ke sekolah lagi.

More casual alternative:

Saya risau adik saya akan ponteng sekolah lagi.

How would I say “I’m not worried that my younger sibling will skip school again”?

You negate the adjective bimbang with tidak:

Saya tidak bimbang adik saya akan ponteng sekolah lagi.

Structure:

Saya – I
tidak bimbang – am not worried
adik saya akan ponteng sekolah lagi – that my younger sibling will skip school again

How is bimbang pronounced, especially the ng at the end?

Pronunciation tips:

bim-: like “bim” in “Bimbo” (short i, as in “bit”).
-bang: the ng is a single nasal sound as in English “sing”, not a hard g.

So bimbang is roughly: [bim-bahng], with ng nasal, not [bim-bang-g].