Learn Hardcore Indonesian: Siapa pun boleh bertanya setelah presentasi selesai. - Anyone may ask questions after the presentation is finished.

It turns the question word siapa (who) into an indefinite form meaning whoever/anyone. So siapa pun = anyone, whoever. Outside this construction, pun can also mean even (as in saya pun datang = I even came), but here it makes an open, non-specific reference.

Why is siapa pun written as two words? I’ve seen siapapun online.

Standard spelling (PUEBI) writes pun as a separate particle in combinations like siapa pun, apa pun, kapan pun, di mana pun. Some forms do fuse (e.g., walaupun, meskipun, sekalipun, bagaimanapun, ataupun, adapun), but not siapa pun. You’ll see siapapun informally, but it’s nonstandard.

Is siapa pun the same as siapa saja?

Yes, in most contexts both mean anyone/whoever. Nuance: siapa pun can feel a touch more formal or written; siapa saja is very common in speech. Your sentence works with either: Siapa pun/Siapa saja boleh bertanya…

Does boleh mean may or can? How is it different from bisa or dapat?

boleh = may, is allowed (permission).
bisa = can (ability, possibility).
dapat = can (ability/possibility), often slightly more formal.
Here, boleh is correct because you’re granting permission to ask.

Do we need the word for question (pertanyaan) here?

No. bertanya already means to ask (a question). If you want to mention questions explicitly, you can say: …boleh mengajukan pertanyaan… (may submit/ask questions).

Is bertanya transitive? How do I say ask someone or ask something?

bertanya is intransitive. Use prepositions:

ask someone: bertanya kepada Budi (ask Budi)
ask about something: bertanya tentang jadwal For a direct object, use the transitive verb family:
menanyakan sesuatu (kepada seseorang) = ask about something (to someone)
menanyai seseorang = question someone (often repeatedly) Colloquial: tanya Budi / nanya Budi.

Should there be untuk before bertanya (e.g., boleh untuk bertanya)?

No. Say boleh bertanya, not boleh untuk bertanya. Adding untuk here is unnecessary and sounds off.

Why is there no verb like is in presentasi selesai?

Indonesian often omits a copula (to be). presentasi selesai literally reads presentation finished, which functions as a complete clause meaning the presentation is finished. So setelah presentasi selesai = after the presentation is finished.

Do we need yang (e.g., setelah presentasi yang selesai)?

No. yang would create a relative clause (the presentation that is finished), which is not needed. The natural time clause is setelah presentasi selesai or setelah presentasi berakhir.

Should it be presentasi or presentasinya?

Both are possible. presentasi can already be definite from context. presentasinya explicitly marks definiteness (that specific presentation). Your sentence is fine as is; use -nya if you want to be extra specific.

Can I move the time clause to the front?

Yes: Setelah presentasi selesai, siapa pun boleh bertanya. When the adverbial clause comes first, add a comma.

What’s the difference between setelah and sesudah?

They’re synonyms meaning after. sesudah can sound a bit more formal or traditional in some ears, but both are widely used.

Is selesai the only option? What about berakhir, usai, kelar?

All work with register differences:

selesai = finished (neutral)
berakhir = ended (neutral)
usai = over (formal/journalistic)
kelar = done (informal/slang) Examples: setelah presentasi berakhir/usai/kelar (the last is casual).

Should there be a comma in the original sentence?

Not when the time clause is at the end: Siapa pun boleh bertanya setelah presentasi selesai. Use a comma only if you front the time clause.

Can I drop selesai and just say after the presentation?

Yes: …setelah presentasi. Adding selesai emphasizes completion, but setelah presentasi is common and clear in context.

Is there a more formal way to make this announcement?

Examples:

Hadirin dipersilakan mengajukan pertanyaan setelah presentasi selesai.
Silakan menyampaikan pertanyaan setelah presentasi berakhir.
Sesi tanya jawab akan berlangsung setelah presentasi.

Can I add sudah (already) before selesai?

You can: setelah presentasi sudah selesai. It adds emphasis that the presentation is indeed already finished, but it’s optional. The shorter setelah presentasi selesai is perfectly natural.