Learn Hardcore Indonesian: Saya mengerjakan kuis itu sambil mendengar musik pelan di headphone baru saya. - I do that quiz while listening to soft music on my new headphones.

Mengerjakan comes from the root kerja (work), with the prefix meN- and suffix -kan, and it literally means to work on / to do (an assignment/task).

In this sentence, Saya mengerjakan kuis itu is most naturally understood as:

I did that quiz / I worked on that quiz.

Nuances:

mengerjakan – used for tasks, assignments, homework, tests, jobs.
- mengerjakan PR = to do homework
- mengerjakan ujian = to take/do an exam
melakukan – more general “to do / to carry out” an action, an activity, an event.
- melakukan penelitian = to conduct research
- melakukan kesalahan = to make a mistake
membuat kuis – usually means to create a quiz, not to take it.
- Guru itu membuat kuis untuk murid-muridnya. = The teacher made a quiz for the students.

So for a student taking/doing a quiz, mengerjakan kuis is the natural choice.

Why is itu used after kuis (kuis itu) if English just says “the quiz”?

Indonesian doesn’t have articles like the or a/an, so demonstratives like itu (that) and ini (this) often play a similar role.

kuis itu can mean:
- that quiz (specific, maybe already mentioned or known from context), or
- the quiz (the specific one you’re talking about).

Without itu:

Saya mengerjakan kuis.
This is more generic: I did a quiz / I was doing a quiz. It sounds less specific.

With itu:

Saya mengerjakan kuis itu.
Implies you and your listener both know which quiz (e.g., the one from yesterday’s class, the one on the website we talked about, etc.).

So itu gives specificity, similar in function to the or that in English.

What does sambil do in this sentence, and how is it different from sementara, ketika, or saat?

Sambil indicates two actions happening at the same time, done by the same subject, with a nuance of “while doing X, (also) doing Y.”

In Saya mengerjakan kuis itu sambil mendengar musik pelan...:

The same person (saya) is doing both:
- mengerjakan kuis itu (doing the quiz)
- mendengar musik pelan (listening to soft music)
Both actions are simultaneous.

Comparison:

sementara / ketika / saat = “while / when,” focusing more on time than on one person doing two things at once. They don’t require the same subject.
- Sementara saya mengerjakan kuis, adik saya bermain game.
  = While I did the quiz, my younger sibling played games.
- Two different subjects: saya and adik saya.

If you change sambil to sementara in the original sentence, it still can be understood, but sambil is the natural, idiomatic choice for “I did X while (I was also) doing Y.”

Why is it mendengar musik pelan and not mendengarkan musik pelan? What’s the difference?

Both mendengar and mendengarkan are correct, but there is a nuance:

mendengar = to hear / to listen (more neutral)
mendengarkan = to listen to (more active, deliberate)

In practice, many native speakers alternate between them quite freely, especially in casual speech.

In this sentence:

sambil mendengar musik pelan = while listening to soft music.
If you say:
sambil mendengarkan musik pelan, it sounds slightly more deliberate: you’re actively listening.

Both are natural here; mendengar is just a bit shorter and more neutral.

Why is it musik pelan (noun + adjective), not pelan musik like in English “soft music”?

In Indonesian, the normal order is:

Noun + Adjective

So:

musik pelan = soft music
buku baru = new book
rumah besar = big house

Putting the adjective first (pelan musik) is ungrammatical.

Here, pelan means slow/soft/quiet depending on context. With musik, it implies soft/quiet (not loud) music.

You could also say:

musik yang pelan – grammatically correct, a bit more descriptive/emphatic, but musik pelan is perfectly natural and more concise.

Is musik pelan the most natural way to say “soft music,” or are there other common options?

Musik pelan is understandable and used, but you may also hear:

musik lembut – gentle/soft music
musik tenang – calm/soothing music
musik santai – relaxed/chill music

Nuances:

pelan – focuses more on low volume / unhurried tempo.
lembut – “gentle,” can be about feel/mood as well as volume.
tenang – calming, not necessarily only about volume.

In everyday speech, musik pelan is fine and natural for “soft/quiet music,” especially if you mean “not loud.”

Why is the preposition di used in di headphone baru saya? Would dengan or pakai be more natural?

Di usually means “in/at/on,” but with devices like headphones, there is some flexibility.

di headphone baru saya – literally “on/in my new headphones.”
- Emphasizes the location of the sound: the music is in/through the headphones.

More common alternatives you’ll also hear:

dengan headphone baru saya = with my new headphones
pakai headphone baru saya = using my new headphones

All are understandable and used in real life. Many speakers would probably say:

... sambil mendengarkan musik pelan dengan headphone baru saya.
... sambil mendengarkan musik pelan pakai headphone baru saya.

So di is not wrong, but dengan or pakai might sound more natural in many contexts.

Why is it headphone baru saya, not headphone saya baru? How does the word order work for baru and saya?

The typical order is:

Noun
Adjective(s)
Possessor (pronoun or noun)

So:

headphone baru saya
- headphone = noun
- baru = adjective (new)
- saya = possessor (my)

This means “my new headphones”.

If you say:

headphone saya yang baru
- also means my new headphones, but with a slight emphasis or contrast, something like “the new one(s) of mine” (as opposed to the old ones).

But headphone saya baru (without yang) is not idiomatic here. You’d normally need yang if you put the adjective after the possessor:

✅ headphone saya yang baru
❌ headphone saya baru (sounds incomplete/odd)

So headphone baru saya is the neat, standard form.

In Indonesian, how do you know if headphone is singular or plural? Does this sentence mean one headphone or headphones?

Indonesian usually doesn’t mark singular vs plural unless it needs to be explicit.

Headphone baru saya could mean:

my new headphone (if there’s only one)
my new headphones (the normal case in real life)

Context normally clarifies it. If you want to be explicit, you can add:

satu headphone baru saya = my one new headphone (rare context)
sepasang headphone baru saya = my new pair of headphones
dua headphone baru saya = my two new headphones, etc.

In everyday usage, listeners will naturally assume “my new headphones.”

Can saya be omitted anywhere in this sentence, and would it still be natural?

Several elements can be omitted in casual Indonesian, depending on context:

Full sentence:

Saya mengerjakan kuis itu sambil mendengar musik pelan di headphone baru saya.

Possible reductions:

Omit the subject saya, if it’s clear from context who is speaking:
- Mengerjakan kuis itu sambil mendengar musik pelan di headphone baru saya.
  In conversation, this is still natural if listeners know you’re talking about yourself.
Omit the second saya (the possessor), if ownership is obvious:
- Saya mengerjakan kuis itu sambil mendengar musik pelan di headphone baru.
  This can work in context, but you lose explicit “my.” Usually you’d keep saya to be clear.
In very casual speech (especially text/online):
- Aku ngerjain kuis itu sambil dengerin musik pelan pakai headphone baru.
  (subject and possession understood from context)

In careful or written Indonesian, keeping both sayas is clear and correct.

If Indonesian doesn’t mark tenses like English, how do we know this sentence is past (“I did the quiz”), not present or future?

Indonesian verbs do not change form for tense. Mengerjakan itself doesn’t indicate past, present, or future.

The time is determined by:

Context, or
Time adverbs like tadi (earlier), kemarin (yesterday), besok (tomorrow), etc.

Your sentence, as-is, can mean:

I am doing that quiz while listening to soft music... (present)
I did that quiz while listening to soft music... (past)
I will do that quiz while listening to soft music... (future) – less likely, but possible with context.

To make it clearly past, you might say:

Tadi saya mengerjakan kuis itu sambil mendengar musik pelan di headphone baru saya.
= Earlier, I did that quiz while listening to soft music on my new headphones.

So, without extra words, the time is understood purely from context.

How formal is this sentence? Would a younger speaker say it differently to a friend?

Using saya makes the sentence neutral to slightly formal.

To a friend, many speakers would switch to aku and use more colloquial verb forms:

Aku ngerjain kuis itu sambil dengerin musik pelan pakai headphone baruku.

Changes:

saya → aku (less formal “I”)
mengerjakan → ngerjain (spoken, relaxed form)
mendengar → dengerin (spoken form, plus -in variant)
di / dengan → pakai (very common in speech, “using”)
headphone baru saya → headphone baruku (using -ku for “my”).

Your original sentence is perfectly good standard Indonesian, suitable for writing, class answers, or polite conversation.

Are there other natural ways to say the whole sentence with the same meaning?

Yes. Here are a few common, natural variants with the same basic meaning:

Saya mengerjakan kuis itu sambil mendengarkan musik pelan dengan headphone baru saya.
- Uses mendengarkan and dengan; slightly more explicit/standard.
Tadi saya mengerjakan kuis itu sambil mendengarkan musik pelan di headphone baru saya.
- Adds tadi to clearly mark past time.
(Informal)
Aku ngerjain kuis itu sambil dengerin musik pelan pakai headphone baruku.
- Very common in casual speech among friends.

All of these convey: I did that quiz while listening to soft music on my new headphones.