Kadang-kadang saya curhat kepada kakak perempuan saya ketika saya gelisah.

Kadang-kadang means sometimes.

The repetition is called reduplication, and it is very common in Indonesian. In this case, kadang by itself can relate to occasion or sometimes, but kadang-kadang is the standard everyday way to say sometimes.

So:

• kadang-kadang = sometimes

You may also hear:

• terkadang = sometimes, occasionally
• kadang = sometimes, but less standard-sounding on its own in many contexts

Curhat is a very common informal Indonesian word. It means something like:

• to open up
• to vent
• to share your feelings/problems
• to confide in someone

It comes from curahan hati, literally something like an outpouring of the heart.

So saya curhat kepada kakak perempuan saya means that the speaker shares their worries or feelings with their older sister.

A key point: curhat is conversational and natural, but not especially formal. In very formal Indonesian, people might use more standard expressions instead.

Kepada marks the person receiving the action, especially in somewhat standard or careful Indonesian. Here, it shows to whom the speaker is opening up.

So:

• curhat kepada kakak perempuan saya = confide to my older sister

In everyday speech, many people would also say:

• curhat ke kakak perempuan saya

That is more casual.
So the difference is roughly:

• kepada = more standard, slightly more formal
• ke = more colloquial in this kind of sentence

It means specifically my older sister.

In Indonesian:

• kakak = older sibling
• adik = younger sibling

If you want to specify gender:

• kakak perempuan = older sister
• kakak laki-laki = older brother
• adik perempuan = younger sister
• adik laki-laki = younger brother

So kakak perempuan saya is not just any sister. It is clearly my older sister.

Saudara perempuan saya does mean my sister, but it sounds more formal, more distant, and less natural in many everyday situations.

Compare:

• kakak perempuan saya = my older sister, natural and specific
• saudara perempuan saya = my sister, more formal or bookish

Also, saudara can sometimes sound broader or more formal than the words people usually use for family in daily conversation.

So in a sentence about personal feelings and family, kakak perempuan saya sounds much more natural.

In Indonesian, possession usually comes after the noun.

So:

• kakak perempuan saya = older sister my = my older sister
• rumah saya = house my = my house
• teman saya = friend my = my friend

This is one of the most basic word-order differences from English.

It is used once as the subject of the main clause and once as the subject of the time clause.

• saya curhat ... = I confide/open up ...
• ketika saya gelisah = when I am anxious/restless

Indonesian often repeats pronouns where English might also repeat them. This is perfectly normal.

Could the second saya be omitted? In some contexts, yes, especially if the meaning is very clear. But keeping it makes the sentence clear and natural.

Yes. Ketika means when in this sentence.

It introduces a time clause:

• ketika saya gelisah = when I am anxious/restless

Other common words you might see are:

• saat = when, at the time when
• waktu = when / time
• kalau = if, and sometimes when in casual speech

Ketika is a good standard choice and sounds natural here.

Gelisah means something like:

• restless
• uneasy
• anxious
• agitated

It describes an uncomfortable emotional state. Depending on context, it can overlap with worried, nervous, or troubled, but gelisah often has a sense of inner unease or restlessness.

So ketika saya gelisah means when I feel uneasy/anxious.

Yes, it is very normal.

The structure is:

• Kadang-kadang = time/frequency expression
• saya = subject
• curhat = verb
• kepada kakak perempuan saya = recipient phrase
• ketika saya gelisah = time clause

So literally, it is something like:

• Sometimes I confide to my older sister when I am anxious.

Indonesian often puts time expressions like kadang-kadang near the beginning of the sentence.

It is a mix of standard grammar and informal vocabulary.

• curhat is informal and very conversational
• kepada is more standard/formal than ke
• the rest of the sentence is neutral and natural

So the overall sentence sounds perfectly understandable and natural, but slightly mixed in register. In everyday speech, many people might say:

• Kadang-kadang saya curhat ke kakak perempuan saya ketika saya gelisah.

That version sounds a bit more casual.

Yes, sometimes it can.

For example:

• Saya curhat sama kakak saya.
• Saya curhat ke kakak saya.

In colloquial Indonesian, sama and ke are both common after curhat.

You can also use curhat without immediately naming the listener if the context is already clear:

• Saya ingin curhat. = I want to open up / vent.

So curhat is quite flexible in casual use.

Because kakak by itself already means older sibling, without specifying male or female.

So:

• kakak saya = my older sibling / my older brother / my older sister, depending on context
• kakak perempuan saya = my older sister

The word perempuan is added to make the gender explicit.

Yes, in many contexts.

Compare:

• saya = I; neutral, polite, standard
• aku = I; more casual and personal

So a more casual version would be:

• Kadang-kadang aku curhat ke kakak perempuanku ketika aku gelisah.

That sounds more intimate and conversational.

The original sentence with saya is more neutral and broadly appropriate.

Because perempuan is describing kakak, so it comes after the noun it modifies.

In Indonesian, modifiers often come after the noun:

• kakak perempuan = female older sibling
• anak kecil = small child
• rumah besar = big house

So kakak perempuan saya is the normal order.

Sometimes, depending on context, curhat can include a sense of complaining or venting. But its meaning is broader and more emotional than just complain.

It often suggests:

• sharing feelings
• opening up emotionally
• telling someone about your problems

So confide in, open up to, or vent to are usually better translations than just complain to.