Peraturan tertentu berlaku di sini.

In Indonesian, adjectives and adjective-like words usually come after the noun they describe.

So:

• peraturan tertentu = certain rules / certain regulations

This is the normal Indonesian word order. English often puts this kind of word before the noun, but Indonesian usually puts it after.

Compare:

• rumah besar = big house
• orang asing = foreign person / stranger
• aturan khusus = special rule

So peraturan tertentu is completely natural Indonesian word order.

It can mean either singular or plural, depending on context.

Indonesian nouns usually do not change form for singular vs. plural. So:

• peraturan can mean a rule / a regulation
• peraturan can also mean rules / regulations

In this sentence, English usually translates it as Certain rules apply here or Certain regulations apply here, so the plural sense is often the most natural.

If Indonesian wants to make the plural very explicit, it can use reduplication:

• peraturan-peraturan tertentu

But in normal usage, that is often unnecessary.

Tertentu means certain, specific, or particular, depending on context.

In this sentence, it suggests that:

• not all rules are being highlighted,
• but some specific rules are in effect here.

So peraturan tertentu can feel like:

• certain rules
• specific regulations
• particular rules

It is a fairly neutral and somewhat formal word.

Berlaku here means something like:

• to apply
• to be in effect
• to be valid
• to be enforceable

With rules, laws, or regulations, berlaku is a very common word.

Examples:

• Undang-undang itu berlaku mulai hari ini.
  = That law takes effect starting today.
• Aturan ini berlaku untuk semua orang.
  = This rule applies to everyone.

So in Peraturan tertentu berlaku di sini, berlaku means that the rules are in force / applicable here.

Because Indonesian does not use a verb like to be as often as English does.

Also, in this sentence, berlaku is already the main verb, so there is no need for are.

English says:

• Certain rules apply here.

Indonesian says:

• Peraturan tertentu berlaku di sini.

You should not think of it as missing a word. The sentence is already complete:

• peraturan tertentu = subject
• berlaku = verb
• di sini = place expression

So Indonesian is not omitting are here; it simply builds the sentence differently.

Because di here is a preposition meaning in / at / on, and prepositions are written separately from the following word.

So:

• di sini = here
• di rumah = at home
• di kantor = at the office

This is different from di- as a verb prefix, which is written together:

• ditulis = written
• dibuka = opened

A useful rule:

• di
  • place = usually separate
• di-
  • verb = usually attached

So di sini must be two words.

Di sini literally means at/in this place, but in natural English it is usually just translated as here.

So:

• berlaku di sini = applies here

Depending on context, di sini can mean:

• in this place
• here
• in this area
• at this location

It does not always need to be translated very literally.

Yes, it sounds fairly neutral-to-formal, especially because of words like:

• peraturan
• tertentu
• berlaku

This kind of sentence would sound natural in places like:

• signs
• official notices
• regulations
• institutions
• public spaces

In casual speech, people might say things a bit more simply, for example:

• Ada aturan tertentu di sini.
• Aturan tertentu berlaku di tempat ini.

But the original sentence sounds very normal for formal or written Indonesian.

Yes, often you can, but there is a slight nuance.

• aturan = rule, rule set, guideline
• peraturan = regulation, rule, more official-sounding rule

So:

• Aturan tertentu berlaku di sini is possible.
• Peraturan tertentu berlaku di sini sounds a bit more formal or institutional.

In many contexts, both work, but peraturan often feels more like official regulations.

The structure is:

• Peraturan tertentu = subject noun phrase
• berlaku = verb
• di sini = location phrase

So the pattern is:

Subject + Verb + Place

More literally:

• Certain regulations + apply + here

This is a very common and straightforward Indonesian sentence pattern.