Learn Hardcore Indonesian: Kami jalan pelan di lorong sekolah supaya tidak mengganggu murid. - We walk slowly in the school hallway so that we do not disturb the students.

In the sentence Kami jalan pelan di lorong sekolah supaya tidak mengganggu murid, kami implies that the speaker’s group is walking, and the listener is not part of that group.

If the speaker wanted to include the listener (for example, saying “Let’s walk slowly…”), they would use kita:

Kita jalan pelan di lorong sekolah supaya tidak mengganggu murid.
= We (you and I) walk slowly in the school corridor so as not to disturb the students.

Why is it jalan pelan and not berjalan pelan? Is jalan a noun or a verb here?

Jalan can be both:

noun: jalan = road/street
verb: jalan = to walk / to go

In standard, more formal Indonesian, you might expect:

Kami berjalan pelan = We walk slowly

But in everyday spoken Indonesian, it’s very common to drop the ber- prefix and just say:

Kami jalan pelan

So here jalan is a verb meaning to walk, used in a more colloquial style. Both are correct; berjalan just sounds a bit more formal or careful.

What does pelan mean, and what’s the difference between pelan, pelan-pelan, and perlahan?

All of these are related to moving slowly:

pelan = slow / slowly
- Kami jalan pelan. = We walk slowly.
pelan-pelan = slowly, but with a sense of “take it easy / gently / carefully”
- Jalan pelan-pelan ya. = Walk slowly, okay? (softer, more emphatic)
perlahan = slowly (more standard/formal; similar to pelan)
- Kami berjalan perlahan. = We walk slowly.

Nuance:

pelan → neutral, everyday
pelan-pelan → more informal, gentle, often used in spoken language
perlahan → slightly more formal or “bookish”

All would be understood in this sentence, with only small style differences.

Why is it jalan pelan and not pelan jalan? Where do adverbs usually go?

In Indonesian, adverbs like pelan (slowly) usually come after the verb:

jalan pelan = walk slowly
makan cepat = eat quickly
bicara keras = speak loudly

So:

Kami jalan pelan = correct and natural
Kami pelan jalan = sounds odd or wrong in standard Indonesian

There are other possible structures (like berjalan dengan pelan, walk with slowness), but for simple verb + adverb, the adverb normally follows the verb.

What exactly does di lorong sekolah mean? How does lorong sekolah work?

di lorong sekolah breaks down like this:

di = in / at / on (location preposition)
lorong = corridor / hallway
sekolah = school

When you put two nouns together, N1 + N2, it often means “N1 of N2”:

lorong sekolah = the school corridor / the corridor of the school
pintu rumah = the house door / the door of the house
guru matematika = math teacher / teacher of math

So di lorong sekolah = in the school corridor or in the corridor of the school.
You don’t need extra words like “of” or “the” in Indonesian; the combination itself shows the relationship.

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

Supaya introduces a purpose or desired result, similar to so that / in order that / so (that):

supaya tidak mengganggu murid
= so as not to disturb the students

Comparisons:

supaya and agar
- Very similar; agar is slightly more formal, often in writing.
- Kami jalan pelan … supaya/agar tidak mengganggu murid.
biar
- More informal, colloquial version of supaya/agar.
- Kami jalan pelan … biar tidak mengganggu murid.
untuk
- Usually followed by a noun or verb phrase, not a full clause with subject-verb.
- Kami jalan pelan untuk mengurangi kebisingan.
  = We walk slowly to reduce noise.
- You normally don’t say: ✗ untuk tidak mengganggu murid in this exact structure; supaya/agar/biar is better there.

So, supaya here clearly marks the purpose of walking slowly.

Why is it tidak mengganggu and not bukan mengganggu?

Indonesian has two common negators:

tidak → used to negate verbs and adjectives
bukan → used to negate nouns and equational statements (A is B)

Since mengganggu is a verb (to disturb), you must use tidak:

tidak mengganggu = not disturb / not bothering

Examples:

Saya tidak makan. = I am not eating. (verb → tidak)
Ini bukan buku saya. = This is not my book. (noun → bukan)
Dia tidak marah. = She is not angry. (adjective → tidak)
Dia bukan guru. = He is not a teacher. (noun → bukan)

So bukan mengganggu would be incorrect here.

What does mengganggu literally mean? Is it only about noise?

Mengganggu comes from the root ganggu (disturb, bother) with the prefix meng-, which often makes an active verb:

ganggu → mengganggu = to disturb / to bother / to interfere with

It’s not limited to noise. It can mean:

disturbing someone’s concentration
bothering someone emotionally
interrupting someone’s activity
making someone uncomfortable

Examples:

Jangan mengganggu dia, dia sedang belajar.
Don’t disturb him/her; he/she is studying.
Suara motor itu mengganggu saya.
That motorcycle noise bothers me.

So in the sentence, it suggests they walk slowly so their presence (including possible noise) doesn’t disturb the students.

Why is there no plural marker for murid? How do I know if it means student or students?

Indonesian usually does not mark plural with a separate word like “s” in English. Context decides whether a noun is singular or plural.

murid = student / students

In this sentence:

supaya tidak mengganggu murid
In context (a school corridor), it naturally means students in general.

Ways to make plurality explicit:

para murid = the students (collective, often more formal)
murid-murid = students (reduplication often shows plural)
banyak murid = many students

So you could also say:

… supaya tidak mengganggu para murid.
… supaya tidak mengganggu murid-murid.

But murid alone is already fine and commonly used.

Can the supaya clause be moved to the beginning of the sentence?

Yes. Indonesian word order is quite flexible for clauses like this. You can say:

Kami jalan pelan di lorong sekolah supaya tidak mengganggu murid.
Supaya tidak mengganggu murid, kami jalan pelan di lorong sekolah.

Both are correct and natural.

Putting supaya… at the beginning often gives more emphasis to the purpose:

Supaya tidak mengganggu murid, kami jalan pelan…
= In order not to disturb the students, we walk slowly…

Is this sentence formal, informal, or neutral? How would it look in more formal Indonesian?

The original sentence is neutral–informal:

Kami jalan pelan di lorong sekolah supaya tidak mengganggu murid.

Features making it a bit informal:

jalan instead of berjalan
plain murid instead of para murid

A more formal or “textbook” version might be:

Kami berjalan perlahan di koridor sekolah agar tidak mengganggu para murid.

Differences:

berjalan → more standard/formal
perlahan → more formal synonym of pelan
koridor → more formal/technical than lorong (both are understood)
agar → slightly more formal than supaya
para murid → explicitly “the students” in a more formal tone

All versions communicate the same basic idea; they just differ in style.