Learn Hardcore Indonesian: Bagian turunan di jalur itu membuat lutut saya sakit. - The downhill section on that trail makes my knee hurt.

Root verb: turun = to go down, to descend
Noun form: turunan = descent / downward slope / offshoot / derivative / descendant, depending on context

Here, with bagian turunan di jalur itu, it clearly means “the descending/downhill part” of that trail. In other contexts, turunan can mean “descendant” (in family terms) or “derivative” (in math), but not here.

Why is it di jalur itu and not something like pada jalur itu?

di is the normal preposition for physical location: “in/on/at” a place.

di jalur itu = on that trail / on that route

pada is more abstract or formal, and is less common for simple physical location like a trail. You might see pada in written/formal language for time, abstract locations, or after certain verbs, but here di is the natural choice.

What exactly does jalur mean here, and could I use jalan instead?

jalur means something like:

lane / route / track / trail / line

In outdoor or sport contexts, jalur is good for a hiking trail, bike route, race course, etc.

You could say jalan:

jalan = road / street / way

But jalan tends to suggest a regular road or street; jalur is more neutral and fits better for a specific route or track, especially in sports or hiking contexts. So jalur is more precise here.

How does membuat work in this sentence?

membuat literally means “to make,” but it’s also used in a causative sense: “to make something become [adjective].”

Pattern:

X membuat Y [adjective].
“X makes Y [adjective].”

Here:

Bagian turunan di jalur itu (subject: the downhill section of that trail)
membuat (verb: makes)
lutut saya (object: my knee(s))
sakit (complement: sore / hurt)

So: “The downhill section of that trail makes my knee(s) hurt.”

Why is it membuat lutut saya sakit and not membuat sakit lutut saya? Are both possible?

The most natural word order is:

membuat + [object] + [adjective]
membuat lutut saya sakit

You can say membuat sakit lutut saya, but it sounds more formal and a bit stiff, and emphasizes sakit more. Everyday speech almost always uses:

membuat lutut saya sakit
or the casual version bikin lutut saya sakit

So both are grammatically possible, but the version in your sentence is the default, natural one.

Why is it lutut saya and not saya lutut?

In Indonesian, the possessor (pronoun) normally comes after the noun:

lutut saya = my knee
rumah saya = my house
buku saya = my book

You don’t say saya lutut for “my knee”; that word order doesn’t express possession. It would just sound like you’re listing two separate things: “I, knee.”

Colloquially, you may also hear lututku, lutut gue, lutut saya—but the pronoun or possessive form still comes after the noun.

In English we’d say “my knees” (plural). Why is lutut singular here, and how do I say “both knees”?

Indonesian often leaves nouns unmarked for singular/plural, and context fills in the rest.

So lutut saya sakit could mean:

“my knee hurts”
or “my knees hurt”

If you specifically want to show plural, you can say:

kedua lutut saya sakit = both my knees hurt
lutut-lutut saya sakit = my knees hurt (plural marked, but a bit less common in everyday speech)

The original sentence is perfectly natural and is commonly understood as “my knees” in this kind of context.

Does sakit here mean “sore,” “in pain,” or “sick”? How do I know?

sakit is flexible and can mean:

“sick / ill” (for a person overall)
“painful / sore / hurts” (for a body part)

You tell which one from context:

Saya sakit. = I am sick.
Lutut saya sakit. = My knee(s) hurt / are sore.

Since sakit modifies lutut (a body part), in English we’d usually translate it as “sore” or “hurting,” not “sick.”

Could I say Bagian turunan di jalur itu menyakitkan lutut saya instead of membuat lutut saya sakit?

That sounds unnatural.

menyakitkan is usually:

An adjective meaning “painful,” “hurtful” (often emotionally):
- Komentarnya sangat menyakitkan. = His comment was very hurtful.
A formal verb “to cause pain to,” but this is rare in everyday speech.

For physical pain in normal conversation, Indonesians strongly prefer:

membuat lutut saya sakit
or casual bikin lutut saya sakit
or simply Bagian turunan di jalur itu bikin lutut saya sakit.

So stick with membuat … sakit here.

How formal or informal is this sentence? How would it sound in casual speech?

The original:

Bagian turunan di jalur itu membuat lutut saya sakit.

is neutral and acceptable in most situations (spoken and written).

More casual spoken versions might be:

Turunan di jalur itu bikin lutut saya sakit.
Turunan di jalur itu bikin lutut gue sakit. (very informal, using gue for “I/me” around Jakarta)

The structure stays the same; you just swap membuat → bikin and saya → a more casual pronoun if you want.

Can I drop bagian and just say Turunan di jalur itu membuat lutut saya sakit?

Yes, you can.

Turunan di jalur itu membuat lutut saya sakit.

is still natural and will be understood as “The downhill (part) on that trail makes my knees hurt.”

Using bagian makes it explicit that you’re talking about one section of the trail. Without bagian, turunan still implies that you mean the downhill stretch, so in casual conversation dropping bagian is very common.