Learn Hardcore Indonesian: Saya diam di grup chat itu karena perasaan saya campur aduk. - I stay silent in that group chat because my feelings are mixed.

Diam is one of those Indonesian words that can function as both an adjective (“silent”) and a stative verb (“to be silent / stay quiet”).
In Saya diam di grup chat itu, it works like a verb meaning “I stay quiet / I don’t say anything”.

Indonesian often uses adjectives directly as verbs, without an extra “to be”. So:

Saya diam. = I am quiet / I stay quiet.
Dia marah. = He/she is angry.
Mereka senang. = They are happy.

No extra verb like “to be” is needed.

Why is it di grup chat itu and not pada grup chat itu or di dalam grup chat itu?

di is the normal, neutral preposition for location: di rumah, di kantor, di sekolah, di grup chat itu.
pada is more formal and often used in writing or in more abstract contexts (e.g. pada kesempatan ini, pada tanggal 5 Mei). In everyday speech di sounds much more natural here.
di dalam means “inside” and is used when you want to stress being inside the interior of something (a room, a box, etc.). For an online chat group, di grup chat is standard; di dalam grup chat is possible but feels a bit wordy and more literal.

So di grup chat itu is the most natural choice in normal conversation.

Where does itu go in a noun phrase? Can I say itu grup chat instead of grup chat itu?

In Indonesian, demonstratives like ini (this) and itu (that) usually come after the noun:

grup chat itu = that chat group
rumah ini = this house

Putting itu before the noun (e.g. itu grup chat) is possible, but it usually works as a separate element, like pointing something out:

Itu grup chat yang sering sepi. = That’s the chat group that is often quiet.

So:

grup chat itu = a noun phrase: that chat group
itu grup chat = more like that (is the) chat group, used when identifying or pointing.

Why is it perasaan saya and not saya perasaan for “my feelings”?

The basic pattern for possession in Indonesian is:

[thing] + [possessor pronoun]

So:

perasaan saya = my feelings
rumah saya = my house
teman saya = my friend

Saya perasaan is not a valid way to express possession; it would just sound wrong. The possessor pronoun (saya, kamu, dia, etc.) normally comes after the noun it owns.

Why do you say perasaan saya campur aduk instead of saya campur aduk?

Perasaan saya campur aduk literally focuses on your feelings being mixed up, not you as a whole person. This is the natural way to say “my feelings are all mixed up” or “I feel mixed up emotionally.”

Saya campur aduk is grammatically possible, but it sounds odd and unclear; it’s not how people normally express this idea. In practice, you would say:

Perasaan saya campur aduk. = My feelings are all mixed up.
Or use another adjective for yourself: Saya bingung, Saya galau, Saya baper, etc., depending on nuance.

What exactly does campur aduk mean? Is it idiomatic or literal?

Literally, campur = mixed and aduk = stirred, so campur aduk = mixed and stirred together.

Idiomatically, it means:

“all mixed up,” “jumbled,” “a mess,” “all over the place”, especially for feelings or thoughts.

Examples:

Perasaan saya campur aduk. = My feelings are all over the place.
Pikirannya campur aduk. = His/her thoughts are jumbled.

It’s common and natural in both spoken and written Indonesian, and not too informal.

Do I need yang before campur aduk, like perasaan saya yang campur aduk?

You don’t have to use yang here.

Perasaan saya campur aduk. is already complete and natural: My feelings are all mixed up.

Yang is used to introduce a relative clause or to emphasize/identify something. You might see:

Perasaan saya yang campur aduk membuat saya diam.
= It’s my mixed-up feelings that make me stay quiet.

So:

Without yang: simple description.
With yang: adds a nuance of “the one that / the thing that”, often used for emphasis or more complex sentences.

Could I move the karena-clause to the front: Karena perasaan saya campur aduk, saya diam di grup chat itu? Is that correct?

Yes, that’s completely correct and very natural:

Karena perasaan saya campur aduk, saya diam di grup chat itu.

Indonesian allows both orders:

Saya diam … karena perasaan saya campur aduk.
Karena perasaan saya campur aduk, saya diam …

When the karena-clause comes first, it’s common (especially in writing) to put a comma after it, just like in English:
Because …, I …

Is there any difference between saya and aku here? Could I say Aku diam di grup chat itu karena perasaan aku campur aduk?

You can say Aku diam di grup chat itu karena perasaan aku campur aduk, but there are a few points:

Saya vs aku
- saya: more formal, neutral, polite; safe with strangers, in writing, or in mixed situations.
- aku: more informal and intimate; used with friends, family, close peers.
Possessive form
With aku, many speakers prefer perasaanku (with the suffix -ku) instead of perasaan aku:
- Aku diam di grup chat itu karena perasaanku campur aduk.

So, in a casual chat with friends, aku-version is very natural; in neutral or slightly formal context, saya is better.

Is grup chat good Indonesian, or is it just English mixed in?

Grup chat is very common in everyday Indonesian, especially in digital contexts (WhatsApp, Telegram, Line, Discord, etc.). Indonesian borrows a lot of tech and internet terms from English.

More “Indonesian” options include:

grup obrolan (literally chat group)
or a more specific phrase like grup WhatsApp, grup Telegram, etc.

In real-life usage, grup chat and grup WhatsApp are probably what you’ll see and hear most often.

Could I say Saya tetap diam di grup chat itu instead of Saya diam di grup chat itu? What’s the nuance?

Yes, you can. The meaning changes slightly:

Saya diam di grup chat itu
= I’m quiet / I don’t talk in that group chat. (neutral statement)
Saya tetap diam di grup chat itu
= I remain quiet / I stay quiet in that group chat.
This suggests there might be a reason or pressure to speak, but you still choose to remain silent.

Tetap adds a nuance of continuing / not changing your state.