Pikirannya terasa kusut, jadi dia menulis di buku harian sampai merasa lebih tenang.

Pikirannya comes from pikiran (thought, mind, thoughts) + -nya.

Here, -nya means something like his/her/their. So pikirannya means:

• his/her mind
• his/her thoughts

In this sentence, it refers to dia, so it means his/her thoughts or his/her mind.

A useful point: in Indonesian, -nya is very common and can show possession without needing a separate word like his or her.

Pikiran is a noun: thought, mind, thinking as a thing.

Berpikir is a verb: to think.

So:

• berpikir = to think
• pikiran = thoughts / mind

In this sentence, the subject is not he/she thinks, but rather his/her thoughts/mind feels tangled/confused. That is why pikiran is used, not berpikir.

Yes, there is a difference.

• merasa = to feel
• terasa = to feel / to be محسوس / to seem felt, often focusing on how something feels rather than on the person actively doing the feeling

In this sentence:

• Pikirannya terasa kusut = His/her mind felt tangled/confused

  This sounds natural because the sentence describes the state of the mind.

Compare:

• Dia merasa tenang = He/she feels calm
• Suasananya terasa tenang = The atmosphere feels calm

So terasa often sounds a bit more descriptive and less directly personal than merasa.

Literally, kusut means tangled, rumpled, or messy.

It can be used for physical things, like:

• rambut kusut = tangled hair
• baju kusut = wrinkled clothes

But it is also used figuratively for thoughts or feelings:

• pikiran kusut = confused thoughts / a troubled mind

So in this sentence, kusut is metaphorical. It means the person’s thoughts are messy, confused, or all tangled up.

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

It connects the two parts:

• Pikirannya terasa kusut = his/her mind felt confused
• jadi dia menulis di buku harian... = so he/she wrote in a diary...

So jadi shows cause and result.

Be careful: jadi can also mean to become, depending on the sentence. But here it clearly means so.

Because di buku harian means in a diary.

• menulis di buku harian = to write in a diary/journal
• menulis buku harian could sound more like to write a diary as an object, which is less natural for this meaning

The preposition di is used because the person is writing in that place/object.

So:

• menulis di buku harian = write in a diary
• menulis di buku = write in a book/notebook

Buku harian literally means daily book:

• buku = book
• harian = daily

Together, it means diary or journal.

A native English speaker should know that Indonesian often builds meanings this way, with very transparent word combinations.

Because Indonesian often omits the subject when it is already clear from context.

The subject of merasa is still dia. So:

• sampai merasa lebih tenang
• sampai dia merasa lebih tenang

Both can work, but the version without dia is more compact and natural here.

This is very common in Indonesian, especially when the subject does not change.

Here, sampai means until.

So:

• dia menulis di buku harian sampai merasa lebih tenang = he/she wrote in the diary until he/she felt calmer

It marks the endpoint of the action.

Common meanings of sampai include:

• until
• up to
• sometimes arrive in other contexts

But in this sentence, until is the right meaning.

In Indonesian, lebih + adjective means more ....

So:

• lebih tenang = calmer / more calm

Indonesian often does not need to explicitly say than before if the comparison is obvious from context.

So here, lebih tenang means:

• calmer than before
• more at ease than earlier

That is understood automatically.

It can cover all of those ideas depending on context.

Tenang often means:

• calm
• relaxed
• at peace
• not anxious
• quiet/still

In this sentence, because it describes a person’s emotional state, tenang means calm or more at ease.

You know from context, not from the word itself.

Dia can mean:

• he
• she

Indonesian does not normally mark gender in third-person singular pronouns. So the sentence itself does not tell you whether the person is male or female.

The same is true for -nya in pikirannya. It can mean:

• his
• her
• their, in some contexts

You need the surrounding context to know.

Indonesian usually does not mark tense the way English does.

So verbs like:

• terasa
• menulis
• merasa

do not automatically tell you past, present, or future.

Time is understood from:

• context
• time words
• the situation in the story

In this sentence, if the translation shows a past meaning like felt and wrote, that comes from context, not from a special past-tense form.

This is one of the biggest differences from English.

Yes, literally it is something like that.

A very literal breakdown would be:

• pikirannya = his/her thoughts
• terasa = felt
• kusut = tangled/messy

So: His/her thoughts felt tangled.

But in natural English, you would usually say:

• His/her mind felt confused
• His/her thoughts were all tangled up
• He/she felt mentally tangled/confused

So the literal translation helps you understand the Indonesian structure, but the natural English version may sound different.

It is much less natural.

Merasa is usually used with a person or animate experiencer:

• Dia merasa lelah = He/she feels tired
• Saya merasa sedih = I feel sad

With pikiran as the subject, terasa sounds better because it describes how the mind/state feels.

So for this sentence, pikirannya terasa kusut is the natural choice.

It has a very common Indonesian pattern:

[state/situation], jadi [resulting action] sampai [endpoint/result]

Breakdown:

• Pikirannya terasa kusut
  = His/her mind felt confused

• jadi dia menulis di buku harian
  = so he/she wrote in a diary

• sampai merasa lebih tenang
  = until he/she felt calmer

So the sentence moves like this:

1. problem/state
2. response
3. result

That is a very natural way to build longer Indonesian sentences.