Learn Hardcore Indonesian: Kebisingan kecil di luar bisa saja membuat bayi sulit tidur. - The small noise outside can easily make a baby have trouble sleeping.

Kebisingan kecil di luar = subject
- kebisingan = noise (abstract noun)
- kecil = small / slight (adjective modifying kebisingan)
- di luar = outside (prepositional phrase modifying kebisingan)
bisa saja membuat = verb phrase
- bisa = can / may / could
- saja = just / simply (adds nuance, see below)
- membuat = to make / to cause
bayi = object (the thing being affected)
sulit tidur = complement
- sulit = difficult
- tidur = to sleep

Literal pattern:
[Noise] [can indeed cause] [baby] [difficult to sleep].

What is the difference between kebisingan and bising? Why is it kebisingan kecil, not bising kecil?

bising is an adjective: noisy.
- Example: jalan itu bising = that road is noisy.
kebisingan is a noun: noise or noisiness.
- The prefix + suffix ke- … -an often turns adjectives into abstract nouns.
- Example: kebisingan di kota = the noise in the city.

In kebisingan kecil, you need a noun as the subject, so kebisingan (noise) is correct, and kecil modifies that noun: slight noise.

bising kecil would sound odd, because it’s like saying a small noisy without a noun: you’d still be missing “thing” (e.g. suara yang bising kecil is still awkward).

Does kecil here mean “small” or “quiet”? How should I understand kebisingan kecil?

kecil literally means small, but in this context it’s used in the sense of slight / minor / not very big in amount.

So kebisingan kecil ≈ a little noise / minor noise / slight noise, not physically “small-sized” noise.

Compare:

kebisingan besar = loud / major noise
kebisingan kecil = slight / low-level noise

You could also express a similar idea with sedikit kebisingan (a little noise), but kebisingan kecil is perfectly natural.

What does bisa saja mean here? How is it different from just bisa?

bisa = can / may / could.
- Kebisingan kecil di luar bisa membuat bayi sulit tidur.
  = A little noise outside can make it hard for a baby to sleep.
bisa saja adds nuance:
- Often: could easily, might well, can just as well, it’s entirely possible that…
- It can sound a bit more emphatic or a bit more casual, depending on context.

In this sentence, bisa saja softens and emphasizes possibility:

Roughly: Even a small noise outside might well make it hard for a baby to sleep.
or
It’s quite possible that a small noise outside will make it hard for the baby to sleep.

So bisa saja is not stronger in certainty; it highlights that this is a realistic, maybe slightly surprising, possibility.

What is the function of membuat here? Is it like English “make someone do something”?

Yes. membuat (from buat = make) here works like make / cause in English:

Pattern:
membuat + [person/thing] + [adjective/state]

In the sentence:

membuat = make / cause
bayi = the baby (object)
sulit tidur = in a state of finding it hard to sleep

So:

membuat bayi sulit tidur = make the baby find it hard to sleep / cause the baby to have trouble sleeping.

Other examples:

Berita itu membuat dia sedih.
= That news made him/her sad.
Cuaca panas membuat saya lelah.
= Hot weather makes me tired.

Why is it sulit tidur, not sulit untuk tidur? Are both correct?

Both are grammatically possible, but sulit tidur is more natural and concise in everyday Indonesian.

sulit tidur
- Literally: difficult to sleep
- sulit directly modifies the activity tidur.
- Very common: Dia sulit tidur, Anak-anak sulit fokus, etc.
sulit untuk tidur
- Literally: difficult in order to sleep
- Slightly more formal or heavier style; often used in more careful or written language.

In speech, sulit tidur (or the more colloquial susah tidur) is what you’ll hear most.

What is the difference between sulit and susah here? Could I say susah tidur instead?

You can say susah tidur; it’s very common.

Difference in feel:

sulit = difficult (a bit more neutral or formal)
susah = hard / troublesome (more colloquial, everyday speech)

Examples:

Saya sulit memahami teks ini. (more formal/neutral)
Saya susah ngerti teks ini. (more casual)

In this sentence:

Kebisingan kecil di luar bisa saja membuat bayi sulit tidur.
= OK, slightly more neutral.
Kebisingan kecil di luar bisa saja membuat bayi susah tidur.
= Also OK, sounds a bit more conversational.

How do I know if bayi means “a baby”, “the baby”, or “my baby”? There is no article.

Indonesian doesn’t use articles like a or the. bayi is just baby in general; context tells you whether it’s specific or general.

Possible nuances and forms:

bayi
- Could mean a baby in general: “(any) baby”
- Or the baby if context is clear.
seorang bayi
- More clearly a baby / one baby (emphasizes one individual).
bayi itu
- that/that particular baby (definite, like the baby).
bayiku / bayi saya
- my baby.

In this generic statement, bayi is best understood as a baby / babies in general:

Slight noise outside can make a baby have trouble sleeping.

Can the word order be changed? For example, can I move di luar or kecil to another place?

Some movement is possible, but not all options sound natural.

Natural:

Kebisingan kecil di luar bisa saja membuat bayi sulit tidur.
(Original; most natural.)

Also natural:

Kebisingan di luar yang kecil bisa saja membuat bayi sulit tidur.
= A small noise that is outside can make it hard for a baby to sleep.
(More complex, slightly different nuance, a bit clunky for this simple idea.)

Less natural or odd:

Kebisingan di luar kecil bisa saja membuat bayi sulit tidur.
→ Sounds off; kecil needs a clearer position.
Di luar, kebisingan kecil bisa saja membuat bayi sulit tidur.
→ This is actually acceptable as topicalization (putting outside first for emphasis: Outside, even slight noise can…).

But you cannot separate kebisingan and kecil arbitrarily. They function as a noun + its adjective, usually staying together: kebisingan kecil.

Does di luar mean “outside the house”, “outside the room”, or just “outside in general”?

di luar by itself is vague: it simply means outside / outdoors / outside (this space). The specific meaning depends on context:

In a house context, di luar usually implies outside the room or outside the house.
If more precision is needed, speakers add a noun:
- di luar rumah = outside the house
- di luar kamar = outside the room
- di luar gedung = outside the building

Here, with bayi and sleep, most listeners will naturally understand you mean noise outside the room or outside the house where the baby is sleeping.

Is this sentence formal or informal? How would a more casual version look?

The original sentence is neutral; it fits both spoken and written Indonesian.

A more casual version might use simpler or more colloquial words:

Sedikit suara dari luar bisa bikin bayi susah tidur.

Changes:

Sedikit suara instead of kebisingan kecil (less formal, more direct)
bikin instead of membuat (colloquial “make”)
susah instead of sulit (more conversational)

All versions are correct; you’d choose based on how formal or casual you want to be.