Learn Hardcore Indonesian: Alih-alih panik, kami telah duduk tenang dan mendengar instruksi. - Instead of panicking, we have sat calmly and listened to the instructions.

It means instead of. The hyphen is standard (per PUEBI): alih-alih. Writing alih alih without a hyphen is nonstandard. It often starts a sentence or clause to contrast two options.

Is the comma after Alih-alih panik necessary?

Recommended, yes. You’re fronting a contrastive phrase, so a comma helps readability: Alih-alih panik, .... If you insert alih-alih mid-sentence, set it off with commas: Kami, alih-alih panik, ....

Is panik a verb here? Could I say berpanik or memanik?

In Indonesian, panik typically functions as a predicate adjective (stative): Mereka panik “They panicked/are panicking.” Forms like berpanik or memanik are not standard. For “to become panicked,” you can say menjadi panik. For the noun “panic,” use kepanikan.

Why use kami and not kita?

kami = we (excluding the listener)
kita = we (including the listener) Here, kami implies the listener was not part of the group that sat and listened.

What nuance does telah add? Can I use sudah or drop it?

telah marks completed action and is formal/written (news, reports).
sudah is also “already,” more neutral and common in speech.
Omitting it gives a simple statement of what happened. All three are grammatical; choose based on formality and whether you want to highlight completion.

Does telah apply to both duduk and mendengar?

Yes. One telah typically scopes over the whole coordinated predicate: telah [duduk ... dan mendengar ...]. You don’t need to repeat telah, though you can for emphasis in very formal prose.

Is duduk tenang natural? How is it different from duduk dengan tenang, duduk diam, and tetap tenang?

duduk tenang: natural; “sit calmly.”
duduk dengan tenang: slightly more explicit/adverbial; same meaning.
duduk diam: “sit still/quietly” (focus on not moving/talking), not necessarily “calm.”
tetap tenang: “stay calm” (not about sitting specifically).

Should it be mendengar or mendengarkan (or menyimak) for “listened to instructions”?

mendengar = to hear; often used broadly as “listen,” but can sound passive.
mendengarkan = to listen to (more active in modern usage).
menyimak = to listen closely/attentively (common in classroom/briefing contexts). For “listened to the instructions,” mendengarkan or menyimak usually fits better than plain mendengar.

Is instruksi singular or plural here? How do I say “the instructions”?

Indonesian doesn’t mark number by default. instruksi can be singular or plural from context. To specify:

Plural: instruksi-instruksi, beberapa instruksi, sejumlah instruksi
Definite “the”: instruksi itu, instruksi yang diberikan, instruksinya (colloquial definite).

Could I say Alih-alih panik, kami duduk tenang sambil mendengarkan instruksi?

Yes. sambil highlights simultaneity (“while”), making it clear you were sitting calmly and listening at the same time. It’s a nice, natural tweak.

Can alih-alih go in the middle of the sentence?

Yes, for emphasis or style:

Kami, alih-alih panik, telah duduk ...
Or split into two clauses: Kami tidak panik; alih-alih, kami duduk ... Both are acceptable.

Is the sentence formal, neutral, or casual? How could I say it more casually?

With alih-alih and telah, it leans formal/neutral. More casual options:

Bukannya panik, kami duduk tenang dan mendengarkan instruksi.
Very casual speech: Bukannya panik, kami duduk tenang dan dengerin instruksi.
Another casual variant: Daripada panik, kami duduk tenang dan denger instruksi.

Can I replace alih-alih with daripada or bukannya? Any difference?

alih-alih: “instead of,” formal/neutral.
daripada: “rather than,” common in suggestions/choices; very natural in casual speech.
bukannya: “not X (but Y),” slightly more contrastive/corrective. All can fit here; choose by tone and context.

Would mengikuti or other words be better than instruksi or change the meaning?

mengikuti instruksi = to follow/obey instructions.
mendengarkan/menyimak instruksi = to listen (attentively) to instructions. As for the noun:
instruksi: instructions (often formal, from authority).
petunjuk: guidance/directions/how-tos.
arahan: directions/guidance (managerial).
perintah: orders/commands (stronger). Pick the noun/verb pair to match your intended nuance.

Does telah duduk mean “sat down” or “were already seated”?

More like “had already sat/been seated” (state/result). If you want the act of sitting down at that moment, add a cue like segera/langsung duduk. If you just want a simple narrative without aspect emphasis, drop telah: kami duduk tenang dan mendengarkan instruksi.