Rambut adik perempuan saya kusut, jadi Ibu menyisirnya pelan-pelan.

Literally, it breaks down like this:

• adik = younger sibling
• perempuan = female
• saya = my / I

So adik perempuan saya means my younger sister.

A useful comparison:

• adik perempuan = younger sister
• kakak perempuan = older sister
• saudara perempuan = sister / female sibling, more formal or broader

Indonesian usually puts the thing possessed first, and the owner after it.

So:

• rambut adik perempuan saya = the hair of my younger sister

This is normal Indonesian word order for possession.

More examples:

• buku saya = my book
• rumah ibu saya = my mother’s house
• nama teman saya = my friend’s name

So English often goes owner + thing, but Indonesian often goes thing + owner.

Because Indonesian often leaves out the verb to be when describing something.

So:

• Rambut adik perempuan saya kusut literally looks like My younger sister’s hair tangled
• but it naturally means My younger sister’s hair is tangled or was tangled

This is very common in Indonesian:

• Dia sakit = He/she is sick
• Rumah itu besar = That house is big
• Saya senang = I am happy

Tense usually comes from context, not from a separate word like is or was.

For hair, kusut means tangled, messy, or unkempt.

It can also be used more broadly for things that are physically or mentally messy, depending on context. For example:

• rambut kusut = tangled hair
• baju kusut = wrinkled clothes
• pikiran kusut = a confused or troubled mind

In this sentence, because it is talking about hair, kusut is best understood as tangled or messy.

Here jadi means so, therefore, or as a result.

It connects the two clauses:

• Rambut adik perempuan saya kusut = My younger sister’s hair was tangled
• jadi Ibu menyisirnya pelan-pelan = so Mom combed it gently

Be careful: jadi can also mean become in other sentences.

For example:

• Dia jadi marah = He/she became angry

But in your sentence, it is clearly the connector meaning so.

In this sentence, Ibu is capitalized because it is being used like a name or title for Mom/Mother.

So here:

• Ibu = Mom / Mother

Lowercase ibu can also mean:

• mother
• Mrs.
• ma’am

Context tells you which meaning is intended. Because this sentence talks about a family member and uses Ibu as the person doing the action, it most naturally means Mom.

menyisirnya = to comb it / comb her / comb him, depending on context.

It has two parts:

• menyisir = to comb
• -nya = him / her / it / their, depending on context

So the whole word means something like combed it or combed her.

In this sentence, the most likely meaning is combed her hair or combed it, referring back to the tangled hair.

Grammatically, -nya can be a little flexible here.

It could point to:

• the hair = Mom combed it
• or the younger sister, with the understood meaning Mom combed her hair

Because the previous clause talks specifically about hair being tangled, most learners should understand -nya here as referring mainly to the hair.

In natural Indonesian, this kind of shorthand is very common. Speakers do not always repeat rambutnya if the meaning is already obvious.

If someone wanted to be more explicit, they could say:

• Ibu menyisir rambutnya pelan-pelan

This is reduplication, and it is very common in Indonesian.

• pelan = slow, soft, gentle
• pelan-pelan = slowly, gently, carefully, little by little

In this sentence, pelan-pelan sounds very natural and emphasizes a gentle, careful action, which makes sense when combing tangled hair.

Using just pelan is possible in some contexts, but pelan-pelan is more idiomatic here.

It can mean both, depending on context.

With menyisir (to comb), pelan-pelan suggests:

• slowly
• gently
• carefully

So in natural English, the best translation is often gently or slowly and gently.

That is because the idea is not only speed, but also being careful not to hurt the child while combing tangled hair.

saya is the more neutral and polite word for I / my.

So:

• adik perempuan saya = my younger sister

If the speaker were being more casual, they might say:

• adik perempuanku

Both are correct, but they have different tones:

• saya = neutral, polite, standard
• aku / -ku = more casual, personal, intimate

Textbooks and standard written Indonesian often prefer saya.

Yes. Indonesian allows several natural variations. For example:

• Karena rambut adik perempuan saya kusut, Ibu menyisirnya pelan-pelan.
• Rambut adik perempuan saya kusut, maka Ibu menyisirnya pelan-pelan.
• Ibu menyisir rambut adik perempuan saya pelan-pelan karena rambutnya kusut.

These versions are slightly different in style, but the basic meaning stays the same.

Your original sentence is natural and clear:

• first state the situation
• then give the result with jadi