Learn Hardcore Indonesian: Magang yang dia jalani di perusahaan itu membantunya memahami praktik kerja nyata. - The internship that she/he did at that company helped him/her understand real work practice.

In your sentence it is clearly a noun because it is followed by yang and acts as the head of a relative clause (magang yang dia jalani = the internship that he/she did).

What is the overall structure of this sentence? Which part is the subject and which is the main verb?

The sentence:

Magang yang dia jalani di perusahaan itu membantunya memahami praktik kerja nyata.

Breaks down like this:

Subject:
Magang yang dia jalani di perusahaan itu
= The internship that he/she did at that company
Main verb (predicate):
membantunya
= helped him/her
Verb complement (what it helped him/her do):
memahami praktik kerja nyata
= to understand real work practices

So in simpler SVO form:

[Magang ... itu] (The internship ...)
[membantunya] (helped him/her)
[memahami praktik kerja nyata] (understand real work practices).

What does yang do in magang yang dia jalani?

Yang here introduces a relative clause, similar to that/which in English.

Magang = internship
dia jalani = he/she undergoes / he/she does
magang yang dia jalani = the internship that he/she did / underwent

So yang works like:

buku yang saya baca = the book that I read
orang yang saya temui = the person whom I met
magang yang dia jalani = the internship that he/she did

Pattern: > [Noun] + yang + [clause describing that noun]

Why is it dia jalani and not dia menjalani?

Base active sentence (without relative clause):

Dia menjalani magang di perusahaan itu.
= He/She did/underwent an internship at that company.

When you move the object (magang) to the front and turn it into a relative clause, Indonesian usually drops the meN- prefix from the verb:

Dia membaca buku itu. → Buku yang saya baca itu.
Dia menulis surat itu. → Surat yang dia tulis itu.

Similarly:

Dia menjalani magang di perusahaan itu.
→ Magang yang dia jalani di perusahaan itu.

So:

menjalani = meN- + jalan
- -i
When relativized with the object fronted, we remove men-, leaving jalani.

This is a very common pattern in Indonesian relative clauses: > Object that Subject V(meN) → Object yang Subject V(bare)

What does di perusahaan itu mean exactly? Why itu and not the like in English?

Di perusahaan itu literally means “at that company.”

di = at / in / on
perusahaan = company
itu = that / the (demonstrative)

In Indonesian, itu often covers both:

that (specific, already known from context), and
the (definite, known/identifiable).

So di perusahaan itu can be:

at that company (a particular one already mentioned), or
at the company (the specific company in question).

Using itu signals that the speaker assumes the listener knows which company they mean (from context or previous mention).

What does membantunya mean, and what is the function of -nya here?

Membantunya = membantu + -nya

membantu = to help
-nya (attached pronoun) = him / her

So membantunya means “helped him/her”.

It corresponds to membantu dia, but:

membantu dia = help him/her (with a separate word)
membantunya = help him/her (with a clitic pronoun attached to the verb)

In the sentence:

Magang... membantunya memahami...
= The internship helped him/her to understand...

Here -nya refers back to dia mentioned earlier.

What is the difference between membantunya and membantu dia? Can I use both?

Both are grammatically correct and mean “helped him/her”, but there are some nuances:

membantunya
- More compact, slightly more formal/literary, common in written Indonesian.
- The pronoun is attached to the verb.
- Magang itu membantunya memahami praktik kerja nyata.
membantu dia
- Slightly clearer for learners, very natural in speech.
- Pronoun is a separate word.
- Magang itu membantu dia memahami praktik kerja nyata.

Meaning-wise, they are the same in this sentence. Style-wise:

membantunya feels a bit more “tidy” and written.
membantu dia feels more neutral and spoken.

You would not normally say membantu ia in this position; dia or -nya are preferred as objects.

Why is there no untuk before memahami? Could I say membantunya untuk memahami?

In Indonesian, when membantu is followed by another verb, you can usually:

omit untuk, or
include untuk.

Both are acceptable.

Without untuk (very common, natural):
- Magang itu membantunya memahami praktik kerja nyata.
- = The internship helped him/her understand real work practices.
With untuk (also correct):
- Magang itu membantunya untuk memahami praktik kerja nyata.
- = The internship helped him/her to understand real work practices.

Omitting untuk is very common when the structure is [membantu + object + verb]:

Ini akan membantu kamu belajar.
Pengalaman itu membantu saya berkembang.

What does memahami mean compared to mengerti? Are they interchangeable?

Both memahami and mengerti can mean to understand, but there are slight nuances:

memahami
- From paham (understanding).
- Often feels a bit more formal or deeper, like to comprehend.
- Common in academic or professional contexts:
  - memahami konsep, memahami sistem, memahami proses kerja.
mengerti
- Very common everyday word for understand.
- Used in general conversation:
  - Kamu mengerti? = Do you understand?

In this sentence:

memahami praktik kerja nyata
sounds like “understand/comprehend real work practices,” which fits the slightly formal/professional tone.

You could say mengerti praktik kerja nyata, but memahami sounds more natural in this type of sentence.

What does praktik kerja nyata literally mean?

Literally:

praktik = practice (as in practical application)
kerja = work
nyata = real, actual

So praktik kerja nyata ≈ real work practices / real-world work practice / actual working practices.

It contrasts with:

teori (theory)
simulasi (simulation)
latihan di kelas (classroom exercises)

The idea is: the internship helped him/her experience and understand how work really happens in the real world, not just in theory.

Why kerja and not pekerjaan in praktik kerja nyata?

Both come from the same root, but they behave differently:

kerja
- Can be a noun (work), or a verb (to work).
- More flexible, often used in compounds:
  - jam kerja (working hours)
  - tempat kerja (workplace)
  - etika kerja (work ethic)
pekerjaan
- A more clearly noun form: job, occupation, or work tasks.
- Examples: mencari pekerjaan, tugas pekerjaan rumah.

Praktik kerja nyata is a fixed, natural-sounding phrase:

literally "real work practice" (practice of working in real conditions).

Praktik pekerjaan nyata would sound odd and is not normally used in this context.

Can I change the word order to Magang di perusahaan itu yang dia jalani ...? Is that still correct?

You can say:

Magang di perusahaan itu yang dia jalani membantunya memahami praktik kerja nyata.

It is grammatically possible, but it sounds a bit heavier and less natural. Native speakers more often say it in the original order:

Magang yang dia jalani di perusahaan itu...

In the original:

yang dia jalani directly follows magang, clearly linking the relative clause to magang.
di perusahaan itu naturally attaches to jalani (did/underwent at that company).

If you front di perusahaan itu, it’s still understandable, but feels slightly clunky. The original order is the most natural and typical.

Is dia here “he” or “she”? How do Indonesians show gender in this kind of sentence?

Dia is gender-neutral. It can mean:

he
she

Indonesian pronouns generally do not mark gender, so:

dia = he / she
miliknya = his / her
anaknya = his/her child

Context usually tells you whether dia is male or female. If it matters and isn’t clear, people may add a noun:

dia, seorang pria itu... (he, that man...)
dia, seorang wanita itu... (she, that woman...)

In your sentence, dia could be either he or she; the Indonesian version doesn’t specify.