Learn Hardcore Indonesian: Ia berdiri di tengah kerumunan sambil memegang sandal. - He/She stands in the middle of the crowd while holding sandals.

Both mean “he/she.” No gender is marked.
ia is more formal/literary and is mostly used as a subject.
dia is neutral and common in speech; it can be subject or object.
Avoid using ia as an object; use dia or -nya.
- Correct: Saya melihat dia / Saya melihatnya.
- Less natural: Saya melihat ia.

Does ia indicate gender or number?

No. ia is singular third person with no gender. For respect, Indonesians might use beliau (polite “he/she”), but gender is never marked.

Is there any tense in the sentence? How do I say past or ongoing action?

Indonesian has no verb tense. Time is shown with adverbs:

Past: tadi, kemarin, barusan (e.g., Ia tadi berdiri…)
Ongoing: sedang (Ia sedang berdiri…)
Future: akan, nanti (Ia akan berdiri…)

Why is it di tengah and not ke tengah?

di marks location (“at/in”): di tengah = “in the middle.”
ke marks movement toward: ke tengah = “to the middle.” Your sentence describes position, not movement, so di is correct.

What’s the nuance between di tengah and di tengah-tengah?

di tengah-tengah emphasizes “right in the very middle/among,” often more vivid or emphatic than plain di tengah. Both are correct.

What exactly does kerumunan mean? How is it different from keramaian?

kerumunan = a cluster/grouping of people focused in one spot, i.e., “a crowd.”
keramaian = “bustle/commotion” or a busy, lively scene; not necessarily a single cluster. Morphology: kerumunan is a noun formed with ke-…-an from a root related to “gathering.”

Is it redundant to say kerumunan orang?

Not wrong, but often unnecessary—kerumunan already implies people. Use kerumunan orang when you want to specify that the crowd consists of people (as opposed to, say, animals) or for clarity/emphasis.

How does sambil work? Can I replace it with sementara, sedangkan, or seraya?

sambil = “while” for two simultaneous actions by the same subject. Your sentence fits this.
sementara can link clauses with different subjects or times; more neutral.
sedangkan often contrasts two clauses (“whereas”).
seraya is a more literary synonym of sambil.
Example: Ia berdiri sambil memegang sandal (same subject doing both).

Can I move the sambil phrase to another position?

Yes. Common variants:

Di tengah kerumunan, ia berdiri sambil memegang sandal.
Sambil memegang sandal, ia berdiri di tengah kerumunan. Use a comma when fronting the adverbial phrase.

What’s the difference between memegang and the base pegang?

memegang is the standard transitive verb “to hold.”
pegang is the bare root; used in imperatives or informal speech:
- Imperative: Pegang! (“Hold it!”)
- Colloquial: Dia pegang sandal (instead of standard Dia memegang sandal).

Could I use membawa, menggenggam, menenteng, or menjinjing instead of memegang?

memegang: to hold (general).
membawa: to carry/bring (not necessarily in the hand).
menggenggam: to grip/clench in the hand.
menenteng: to dangle/carry by the strap/handle at your side (casual feel).
menjinjing: to carry by hand with arm down (e.g., a bag).
Pick based on the manner of holding.

Is sandal singular or plural here?

Indonesian doesn’t mark plural by default; sandal is ambiguous. To be explicit:

One piece (one of a pair): sebelah sandal
A pair: sepasang sandal
Plural (generic): sandal-sandal or add a number (dua sandal)

How do I show possession, like “his/her sandals”?

Attach -nya to the noun:

sandalnya = “his/her/their/the” sandals (context decides).
So: Ia berdiri … sambil memegang sandalnya.

Is the spelling sandal or sendal?

Standard Indonesian (KBBI) uses sandal. sendal is a common colloquial spelling but is nonstandard in formal writing.

Any notes on pronunciation in this sentence?

ia = two vowels: [i‑a]
berdiri ≈ bə‑RDEE‑ree (first e is schwa)
tengah ≈ tə‑NAH (ng as in “sing”)
kerumunan ≈ kə‑roo‑MOO‑nan
sambil ≈ SAHM‑bil
sandal ≈ SAHN‑dal

Does berdiri mean “to stand” or “to stand up”?

Both, depending on context:

State: “be standing” (Ia berdiri di sana = He is standing there)
Inchoative (stand up): often implied by a prior action or marker (Ia lalu berdiri = He then stood up)

Could I say di antara instead of di tengah?

di tengah (kerumunan) = in the middle of the crowd (most idiomatic here).
di antara = among/between; works well with plural countables (e.g., di antara orang-orang).
di antara kerumunan is understandable but less idiomatic than di tengah kerumunan for this meaning.