Learn Hardcore Indonesian: Saya percaya dia mampu berbicara di depan kelas tanpa panik. - I believe he/she is capable of speaking in front of the class without panicking.

saya: neutral and polite; safe in most contexts (speaking to strangers, at work, in writing).
aku: informal/intimate; with friends, family, or peers. Avoid in formal situations.
gue/gua: very informal Jakarta slang; only with close peers who also use it.

You could swap in aku for a casual tone: Aku percaya…

Does dia mean “he” or “she”? Are there other options?

dia is gender-neutral: it means “he” or “she.”
ia: more formal/literary, mostly as a subject (often in writing). You wouldn’t normally say it after prepositions.
beliau: respectful “he/she” for elders or people of higher status.
Possessive “his/her” is often -nya attached to a noun (e.g., bukunya = his/her book), or you can say punya dia.

Can I add bahwa after percaya (i.e., Saya percaya bahwa…)?

Yes. Both are correct:

Saya percaya dia mampu… (natural, common in speech)
Saya percaya bahwa dia mampu… (a bit more formal/explicit, common in writing)

Adding bahwa just signals clearly that a clause follows.

What’s the difference between mampu, bisa, dapat, and sanggup?

bisa: the default “can” for general ability; very common in speech.
dapat: like “can,” but feels a bit more formal/literary; also means “to get/receive” in other contexts.
mampu: emphasizes capability/competence or capacity (often a bit formal): “be capable of.”
sanggup: “able and willing/ready to take on (cope with) something,” often implying effort or endurance.

Note: For permission, use boleh (“may”). Colloquially people may say bisa for permission, but boleh is clearer.

Do I need untuk after mampu (e.g., mampu untuk berbicara)?

No. The natural pattern is mampu + verb: mampu berbicara. While mampu untuk + verb appears in some writing, many speakers consider it redundant or less natural.

What’s the difference between berbicara, bicara, and ngomong?

berbicara: standard/neutral-to-formal “to speak/talk.”
bicara: slightly more informal but perfectly acceptable in speech: mau bicara dengan…
ngomong: very colloquial (“to talk/say”); use with close friends: ngomong apa sih? Related: membicarakan + object = “to discuss (something).”

Does di depan kelas mean “in front of the class (people)” or “in front of the classroom (the room)”?

It can mean either, depending on context. In this sentence—paired with berbicara—it most naturally means “in front of the class (the audience).” To disambiguate:

People/audience: di hadapan kelas or di depan para siswa/kelasnya
Location (the room): di depan ruang kelas

Can I say di hadapan kelas or di depan para siswa instead?

Yes:

di hadapan kelas = “in the presence of the class” (a bit formal).
di depan para siswa = “in front of the students” (explicit about the audience). Both are good ways to avoid ambiguity.

Why is panik used after tanpa? Isn’t panik an adjective?

In Indonesian, many adjectives can function like nouns after tanpa. So tanpa panik = “without panic/without panicking.” Alternatives:

tidak panik (does not panic) — more direct negation.
tanpa kepanikan uses the abstract noun kepanikan “panic (as a state),” but here it sounds too heavy; tanpa panik is more natural.

Is tanpa merasa panik or tanpa menjadi panik okay?

tanpa merasa panik is grammatically fine but adds “feel,” so it slightly shifts the meaning.
tanpa menjadi panik is not idiomatic. Use tanpa panik or tidak panik instead.

Where should tanpa panik go in the sentence? Can I move it?

Default and most natural: after the verb phrase.

Dia mampu berbicara di depan kelas tanpa panik. Fronting for emphasis is also okay:
Tanpa panik, dia mampu berbicara di depan kelas. Avoid splitting it awkwardly in the middle of the verb phrase.

How do I pronounce the sentence?

Approximate sounds:

Saya [SAH-yah] (a = “ah”)
percaya [pər-CHAH-yah] (c = “ch,” first e = schwa)
dia [DEE-ah]
mampu [MAHM-poo]
berbicara [bər-bee-CHAH-rah]
di [dee]
depan [də-PAHN] (e = schwa)
kelas [kə-LAHS] (e = schwa)
tanpa [TAHN-pah]
panik [PAH-neek] (final k is unreleased in natural speech) R is a tapped or trilled r; vowels are pure and generally not reduced except schwa (e).

What’s the nuance difference between percaya and yakin?

percaya = “believe/trust” (can be belief in a person or a statement).
yakin = “be sure/confident/certain,” stronger and more assertive. So: Saya percaya dia mampu… (I believe) vs Saya yakin dia mampu… (I’m sure).

Should di be written together with depan (like didepan)?

No. As a preposition, di is always written separately: di depan, di rumah, di sekolah. If you see di- attached to a word, that’s usually the passive verb prefix (e.g., diberi, diminta), not the preposition.

What’s the difference between di depan kelas and di kelas?

di depan kelas: “in front of the class/classroom” (location at the front).
di kelas: “in class/in the classroom” (inside, not necessarily at the front). For example, berbicara di kelas could mean “talk in class,” not necessarily giving a presentation.

Can I use a transitive form like membicarakan here?

Different meaning:

berbicara (tentang X) = to speak/talk (about X) in general.
membicarakan X = to discuss X (focus on the topic as an object). Your sentence is about the act of speaking in front of a class, so berbicara is the right choice. If you want to stress the topic, you could say: Dia mampu membicarakan topik itu di depan kelas tanpa panik.