Gerbong barang itu sudah diperiksa oleh petugas sebelum kereta berangkat.

In Indonesian, the main noun usually comes first, and a modifying noun comes after it.

• gerbong = carriage / railcar
• barang = goods / cargo

So gerbong barang literally means cargo carriage or freight car.

This is a very common Indonesian pattern:

• rumah sakit = hospital, literally sick house
• meja makan = dining table, literally eating table
• kereta barang = freight train

So gerbong barang is the natural word order.

Itu after a noun often works like that, but in many contexts it also helps make the noun definite, like the in English.

So:

• gerbong barang = a freight car / freight cars in general
• gerbong barang itu = that freight car / the freight car

In Indonesian, itu often comes after the noun:

• buku itu = that book / the book
• orang itu = that person
• kereta itu = that train

Here, it tells you we are talking about a specific freight car.

Sudah marks that something is already completed or has happened before another point in time.

In this sentence, it shows that the inspection was completed before the train departed.

So sudah diperiksa means something like:

• had already been inspected
• was already inspected
• has been inspected already

Because the sentence also has sebelum kereta berangkat (before the train departed/leaves), sudah helps show the sequence clearly: first the inspection, then the departure.

Because this sentence is in the passive voice.

• memeriksa = to inspect, to examine
  
  • active
• diperiksa = be inspected / was inspected
  
  • passive

Compare:

• Petugas sudah memeriksa gerbong barang itu.
  = The officer/staff already inspected the freight car.

  • active, focus on petugas

• Gerbong barang itu sudah diperiksa oleh petugas.
  = The freight car was already inspected by the officer/staff.

  • passive, focus on gerbong barang itu

Indonesian uses passive quite often, often more naturally than English does.

The prefix di- is a common way to form the passive of a transitive verb in Indonesian.

Here:

• base/root: periksa = inspect / examine
• passive form: di- + periksa → diperiksa = be inspected

A few similar examples:

• dibuka = opened / be opened
• ditulis = written / be written
• dibersihkan = cleaned / be cleaned

So diperiksa literally has the sense of was inspected or got inspected, depending on context.

Because Indonesian does not need a separate verb like was to form the passive.

In English, you usually need:

• was inspected
• is inspected
• has been inspected

In Indonesian, the passive meaning is mainly shown by:

• the verb form itself, such as diperiksa
• time/aspect words such as sudah, sedang, akan
• context

So:

• diperiksa can mean is inspected, was inspected, or be inspected
• sudah diperiksa helps narrow it to a completed action

Indonesian relies much more on context than English does.

Oleh means by in passive constructions.

So:

• oleh petugas = by the officer / by staff / by the official on duty

It marks the agent, meaning the person who performed the action.

Is it necessary? Not always.

If the doer is unknown, unimportant, or obvious, Indonesian often leaves it out:

• Gerbong barang itu sudah diperiksa.
  = The freight car has already been inspected.

Including oleh petugas makes the sentence more explicit and slightly more formal.

Petugas is a broad word. It usually means someone who is on duty or performing an official task, such as:

• officer
• staff member
• official
• attendant
• personnel

The best English translation depends on context. In a railway context, petugas could be:

• railway staff
• an inspector
• an officer
• station personnel

So it is a practical, general word rather than a very specific job title.

Good question. They refer to different parts of the railway system.

• kereta = train
• gerbong = a railcar / carriage / wagon

So:

• kereta berangkat = the train departs
• gerbong barang = the freight car

You can think of kereta as the whole train, while gerbong is one unit attached to it.

Also, in everyday Indonesian, people often say kereta instead of the fuller kereta api for train, especially when the meaning is clear.

Indonesian verbs generally do not change form for tense the way English verbs do.

So berangkat can mean:

• depart
• departs
• departed
• is departing
• leave / leaves / left

The exact time is understood from:

• context
• time words
• aspect markers
• the rest of the sentence

Here, the clause sebelum kereta berangkat means before the train departed or before the train leaves, depending on the broader context. Because the main clause has sudah diperiksa, the overall sentence naturally suggests a completed event before departure.

Berangkat means to depart, to leave, or to set off.

It is an intransitive verb, so it normally does not take a direct object.

Examples:

• Kereta berangkat. = The train departs.
• Saya berangkat pagi. = I leave in the morning.
• Mereka berangkat ke Jakarta. = They left for Jakarta.

The prefix ber- often appears in intransitive verbs, though it has several functions in Indonesian and does not always translate neatly into English.

Yes. Sudah and telah can both mark a completed action.

So you could say:

• Gerbong barang itu sudah diperiksa oleh petugas...
• Gerbong barang itu telah diperiksa oleh petugas...

The difference is mainly style:

• sudah = very common, everyday, natural
• telah = more formal, more written, sometimes more official in tone

In ordinary conversation, sudah is usually more common.

Yes. A natural active version would be:

Petugas sudah memeriksa gerbong barang itu sebelum kereta berangkat.

This means the same basic thing, but the focus changes:

• Passive: Gerbong barang itu is the topic/focus
• Active: Petugas is the topic/focus

Both are correct. Indonesian often chooses passive when the thing affected by the action is more important than the person doing it.