Petugas di loket memberi stempel merah pada berkas saya.

Petugas means an officer, staff member, clerk, or attendant, depending on context. In this sentence, it refers to the person working at the service counter.

It is a fairly general word, so it does not by itself tell you exactly what kind of employee the person is.

Loket usually means a counter, service window, ticket window, or booth. It is the place where a clerk or staff member serves people.

So petugas di loket means the clerk/staff member at the counter.

Because di here is a preposition meaning at, in, or on a place.

• di loket = at the counter

When di- is a passive prefix on a verb, it is written together:

• ditulis = written
• diberi = given / stamped / marked

So:

• di loket → separate, because it is a preposition
• diberi → together, because it is a verb with the passive prefix

Literally, memberi means to give, and stempel means stamp. But together, memberi stempel often means to put a stamp on something.

So this is a very natural Indonesian way to express the idea of stamping a document:

• memberi stempel pada berkas = to put a stamp on the file/document

English usually uses the verb stamp, but Indonesian often uses a phrase like give a stamp.

Yes, memberikan is possible, but memberi sounds more natural and efficient here.

Both can mean to give, but there is a common tendency:

• memberi often focuses on giving something to someone/something
• memberikan is often a bit more formal and can sound slightly more focused on the thing being given

So:

• Petugas di loket memberi stempel merah pada berkas saya.
  very natural

• Petugas di loket memberikan stempel merah pada berkas saya.
  possible, but a bit less direct in everyday use

Because in Indonesian, adjectives usually come after the noun.

So:

• stempel merah = red stamp
• berkas saya = my file/document
• rumah besar = big house

This is one of the most basic Indonesian word-order patterns:

• noun + adjective

In this sentence, pada marks the target of the action. Here it means something like on or to in English.

• memberi stempel merah pada berkas saya
  = to place a red stamp on my file

With memberi, Indonesian often marks the recipient or target with kepada or pada.

In this sentence, pada works well because the target is not a person, but a document.

Usually, pada berkas saya is better here.

Why?

• di is mainly for physical location: in/at/on
• pada is often used for the target of an action, especially in more formal Indonesian

So for stamping a document:

• memberi stempel pada berkas saya = natural
• memberi stempel di berkas saya = understandable, but less elegant in this structure

If you want a version with di, Indonesian would more naturally restructure the sentence, for example:

• Petugas itu memberi stempel merah di berkas saya.

That is possible in speech, but pada berkas saya sounds more standard.

Because Indonesian possession usually works as:

• noun + possessor

So:

• berkas saya = my file
• rumah saya = my house
• nama Anda = your name

This is different from English, where the possessor usually comes first.

Berkas usually means a file, dossier, set of documents, or paperwork. It is commonly used in offices, government services, applications, and administrative situations.

It is more formal and bureaucratic than a general word like kertas (paper).

So berkas saya suggests my file / my documents / my paperwork, not just one sheet of paper.

In this sentence, stempel is a noun: stamp.

That is why it appears after memberi:

• memberi stempel = to give/apply a stamp

Indonesian can also form verbs related to it, for example:

• menstempel = to stamp
• dicap = stamped (using cap, another word for stamp/seal)

So Indonesian may express the idea in different ways:

• memberi stempel pada berkas
• menstempel berkas
• mencap berkas

Yes. A more direct Indonesian verb-based version would be:

• Petugas di loket menstempel berkas saya.

You could also hear:

• Petugas di loket mencap berkas saya.

The original sentence is still very natural, but it uses the memberi + noun pattern instead of a single verb.

So these are all possible, with slightly different style or nuance:

• memberi stempel pada berkas saya
• menstempel berkas saya
• mencap berkas saya

Because Indonesian does not use articles like English a/an/the.

So a noun like petugas can mean:

• a clerk
• the clerk

Which one is intended depends on context.

The same is true for:

• loket = a/the counter
• stempel merah = a/the red stamp
• berkas saya = my file

English requires articles, but Indonesian normally does not.

The structure is:

• Petugas di loket = subject
• memberi = verb
• stempel merah = thing being given/applied
• pada berkas saya = target

So the pattern is roughly:

Subject + Verb + Object + Target

More literally:

The clerk at the counter + gave/applied + a red stamp + to/on my file

This is a very common Indonesian pattern, especially with verbs like memberi.