Petugas memeriksa rel sebelum kereta pertama berangkat.

Petugas is a general word for a staff member, officer, worker, or official on duty. In this sentence, it most naturally means something like railway staff, an inspector, or the personnel responsible for checking the track.

A useful thing to know: petugas does not automatically show singular or plural. So it could mean:

• the officer/staff member checks the track
• the staff/personnel check the track

You usually know from context.

Periksa is the base word meaning check / inspect / examine.
Memeriksa is the normal active verb form built from that base.

So:

• periksa = the root / dictionary form
• memeriksa = to inspect, to check

In a full sentence with a clear subject doing the action, Indonesian often uses this meN- verb form:

• Petugas memeriksa rel. = The staff inspect the track.

If you said just Periksa rel!, that would sound like an order: Inspect the track!

Rel means rail or railway track. In this sentence, it is best understood as the track or the rails that the train runs on.

Depending on context, English may translate it differently:

• rel = rail
• rel-rel = rails
• jalur rel = rail line / track line

Indonesian often does not force you to choose between singular and plural as strictly as English does, so rel here can naturally refer to the railway track in general.

In Indonesian, ordinal numbers usually come after the noun.

So:

• kereta pertama = the first train
• orang kedua = the second person
• bab ketiga = the third chapter

That is the normal pattern. English puts first before the noun, but Indonesian usually puts pertama after it.

Here it means the first train, usually in the sense of the earliest scheduled train or the first train to depart.

It does not usually mean train number one as a label or ID number. If you wanted a numbered train, Indonesian would normally make that clearer with context or different wording.

So in this sentence, kereta pertama berangkat means the first train leaves/departs.

Sebelum means before. It introduces a time clause:

• sebelum kereta pertama berangkat
  = before the first train departs

So the whole sentence means that the inspection happens earlier than the train’s departure.

A very common pattern is:

• sebelum + clause
• before + subject + verb

For example:

• Sebelum dia tidur, dia membaca.
  = Before he sleeps / before going to sleep, he reads.

Because after sebelum, Indonesian commonly uses a full clause with its own subject and verb.

So:

• kereta pertama = subject
• berangkat = verb

Together:

• kereta pertama berangkat = the first train departs

This is very natural Indonesian. It is similar to English before the first train departs.

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

It is usually an intransitive verb, which means it does not take a direct object. A train can berangkat, a person can berangkat, but you do not normally put a direct object after it.

Examples:

• Kereta berangkat pukul enam.
  = The train departs at six.
• Saya berangkat sekarang.
  = I’m leaving now.

The ber- prefix often appears in intransitive verbs, but with common words like berangkat, it is best to learn the whole word as a unit rather than trying to break it down too mechanically.

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

So memeriksa and berangkat do not themselves tell you whether the sentence is past, present, or future. The time is understood from context.

This sentence could mean, depending on context:

• The staff inspect the track before the first train departs.
  (habit/routine)
• The staff inspected the track before the first train departed.
  (past)
• The staff will inspect the track before the first train departs.
  (future plan)

If the speaker wants to make time explicit, Indonesian can add words like:

• sudah = already
• sedang = in the middle of
• akan = will

Indonesian does not normally use articles like the or a/an.

So:

• petugas can mean a staff member, the staff member, or staff
• rel can mean a rail, the track, or rails
• kereta pertama can mean the first train

Whether something is definite or indefinite usually comes from context, not from a separate word like the.

That is why English translations often add the, even though Indonesian does not have it in the sentence.

Yes. Indonesian nouns usually do not show number unless something in the sentence makes it clear.

So petugas could mean:

• the officer
• the staff member
• the staff
• the personnel

If you wanted to make it clearly plural, you could sometimes use:

• para petugas = the officers / the staff members
• petugas-petugas = staff members (reduplicated form)

But in many real sentences, plain petugas is enough.

Yes. That version is completely natural and means the same thing:

• Petugas memeriksa rel sebelum kereta pertama berangkat.
• Sebelum kereta pertama berangkat, petugas memeriksa rel.

The difference is mainly emphasis and flow.

• Starting with Petugas... highlights who does the action first.
• Starting with Sebelum... highlights the time condition first.

Both are correct.