Learn Hardcore Indonesian: Besok dia ingin mencoba lagi agar berhasil. - Tomorrow she/he wants to try again to succeed.

Besok dia ingin mencoba lagi agar berhasil. (Time is fronted; common.)
Dia ingin mencoba lagi besok agar berhasil. (Time at the end; also common.)
Agar berhasil, dia ingin mencoba lagi besok. (Purpose is fronted for emphasis.)

Do I need akan to talk about the future here?

No. The time word Besok already signals the future, and Indonesian verbs don’t inflect for tense. You can add akan for a neutral “will/going to” sense:

Besok dia akan mencoba lagi agar berhasil. Using ingin expresses desire/intention (“wants to”), while akan is a neutral future marker. Don’t combine them as akan ingin.

What’s the difference between ingin, mau, and pengen/pingin?

ingin: want/would like; neutral to formal and polite. Fits well in writing.
mau: want/will; very common in speech; can also imply an upcoming plan (near-future).
pengen/pingin: colloquial/slang for “want”; use it only in informal contexts.
All three can work in this sentence, with register differences:
Formal/neutral: Besok dia ingin mencoba lagi...
Casual: Besok dia mau coba lagi...
Very casual: Besok dia pengin/pingin coba lagi...

When do I use mencoba versus coba?

mencoba is the standard verb “to try” (root coba with the meN- prefix). Use it in neutral/formal contexts: Dia ingin mencoba lagi.
coba without the prefix is common in speech and in imperatives: Coba lagi! In casual speech you may hear Dia mau coba lagi, which is fine informally.
Colloquial forms include nyoba (“try”), from mencoba.

Is ingin untuk mencoba correct?

It’s better to say simply ingin mencoba. The untuk is usually unnecessary (and often labeled redundant) when ingin is followed by another verb:

Prefer: Dia ingin mencoba lagi...
Avoid: Dia ingin untuk mencoba lagi...

What does lagi mean here, and where should it go?

Here lagi means “again” and follows the verb: mencoba lagi = “try again.” Be careful: lagi before a verb usually marks a progressive (“is/are doing”):

Dia lagi mencoba = “He/She is trying (right now).”
Dia mencoba lagi = “He/She tries again.” You can combine both if needed: Dia lagi mencoba lagi = “He/She is trying again.”
Other meanings: lagi can also mean “more” (e.g., satu lagi = “one more”).

What does agar do? How is it different from supaya and biar?

agar is a subordinator meaning “so that/in order that,” introducing a purpose clause.

agar: more formal/written.
supaya: neutral and common in speech and writing.
biar: casual/informal. All are fine with register adjustments:
Besok dia ingin mencoba lagi agar/supaya/biar berhasil.

Can I use untuk instead of agar? Is untuk berhasil okay?

Yes, but note the nuance:

agar/supaya introduce a clause with an (often understood) subject: (agar [dia] berhasil) = “so that (he/she) succeeds.”
untuk introduces a purpose phrase: untuk berhasil = “to succeed / for the purpose of succeeding.” Both are acceptable here:
Dia ingin mencoba lagi agar berhasil.
Dia ingin mencoba lagi untuk berhasil. Use agar/supaya when you want a clear “so that” sense. Use untuk for a more “to/for” purpose feel. Avoid ingin untuk mencoba (see earlier).

Is agar berhasil missing a subject? Should it be agar dia berhasil?

Indonesian often omits the subject in the purpose clause when it’s the same as the main subject. So agar berhasil implicitly means “so that he/she succeeds.”
You can include it for clarity or contrast:

Dia ingin mencoba lagi agar dia berhasil.
If the subject changes, you must state it: Dia ingin mencoba lagi agar timnya berhasil.

What exactly does berhasil mean? How is it different from sukses?

berhasil (ber- + hasil “result/outcome”) is an intransitive verb meaning “to succeed / to be successful” and often functions like “manage to”:
- Dia berhasil. = “He/She succeeded.”
- Dia berhasil memenangkan lomba. = “He/She managed to win the competition.”
- You can also say berhasil dalam ujian = “succeed in the exam.”
sukses (loanword) can be a noun or adjective (“success/successful”). In many contexts it overlaps with berhasil:
- agar sukses is fine and common, slightly more colloquial.
Antonym: gagal (“fail”): agar tidak gagal = “so that (he/she) doesn’t fail.”

Does dia mean “he” or “she”? What about ia and beliau?

dia is gender-neutral: “he” or “she.”
ia is a more formal/literary subject pronoun; often appears only as a subject in writing: Ia ingin mencoba...
beliau is a respectful third-person pronoun for elders or respected figures.
In everyday speech, dia is the default. Indonesian does not mark grammatical gender.

Can I omit dia?

Yes, Indonesian allows dropping the subject when it’s clear from context. You might hear or see:

Besok ingin mencoba lagi agar berhasil. This is grammatical but can be ambiguous out of context. In careful writing, keeping dia is clearer.

Do I need a comma after Besok?

No. A comma is not required after a short fronted time adverb. Besok dia ingin... is standard. Some writers add a comma for a pause after longer introductory phrases, but it’s optional and not needed here.

What’s the difference between agar and sehingga?

agar/supaya/biar express purpose (“so that / in order that”): Dia mencoba lagi agar berhasil.
sehingga expresses result/consequence (“so that/as a result”): Dia mencoba lagi, sehingga dia berhasil.
They’re not interchangeable in meaning: purpose vs. outcome.