Stopkontak di kamar tamu longgar; tolong periksa dulu.

Stopkontak means electrical outlet / power socket.

It is commonly written as one word in Indonesian. You may also see people talk about colokan in everyday speech, but stopkontak specifically refers to the wall outlet itself.

So in this sentence, Stopkontak di kamar tamu means the outlet in the guest room.

Indonesian often does not use a verb meaning to be in simple sentences like this.

So:

• Stopkontak di kamar tamu longgar
• literally: The outlet in the guest room loose
• natural English: The outlet in the guest room is loose

This is completely normal in Indonesian. Adjectives can function directly as predicates without adalah.

Longgar usually means loose, not tight, or not firmly attached.

In this sentence, it means the outlet is loose in the wall or not securely fitted. It does not mean emotionally relaxed or casual here; it is a physical description.

Other examples:

• Bajunya longgar = The clothes are loose
• Sekrupnya longgar = The screw is loose

Di is the preposition meaning in / at / on, depending on context.

So:

• di kamar tamu = in the guest room

This phrase tells you where the outlet is. It comes after stopkontak to specify which outlet is being talked about:

• stopkontak di kamar tamu = the outlet in the guest room

Indonesian does not have articles like a, an, or the.

Whether something is understood as a socket or the socket depends on context. In this sentence, English naturally translates it as the outlet in the guest room, but Indonesian does not need a separate word for the.

In Indonesian, the object is often left unstated if it is already obvious from context.

So tolong periksa dulu literally means:

• please check first

But in context, everyone understands that it means:

• please check the outlet first

If you wanted to make the object explicit, you could say:

• Tolong periksa stopkontaknya dulu.

That sounds a bit more explicit, but the shorter version is very natural.

Tolong is a very common way to make a request more polite. In many situations, it works like please.

So:

• Periksa dulu. = Check it first.
  This is more direct.
• Tolong periksa dulu. = Please check it first.
  This sounds more polite.

It is especially common in instructions, requests, and service situations.

Yes, dulu can mean before / in the past, but in requests and commands it often means first.

Here, tolong periksa dulu means:

• please check first
• please check it before doing anything else

This use of dulu is extremely common.

Examples:

• Makan dulu. = Eat first.
• Tunggu dulu. = Wait a moment / wait first.
• Periksa dulu. = Check first.

So in this sentence, dulu does not mean past time.

Yes, both are possible, but they are slightly different in tone.

• periksa = more standard, neutral, slightly more formal
• cek = common in casual speech, borrowed from English check

So these are both natural:

• Tolong periksa dulu.
• Tolong cek dulu.

If you want slightly more standard Indonesian, periksa is a good choice.

The semicolon separates two closely connected ideas:

1. Stopkontak di kamar tamu longgar
2. tolong periksa dulu

It shows that the second part is a response or instruction related to the first part.

In everyday writing, people might also use:

• a period: Stopkontak di kamar tamu longgar. Tolong periksa dulu.
• a comma: Stopkontak di kamar tamu longgar, tolong periksa dulu.

The semicolon is just a neat written way to join the two related clauses.

Yes, it could.

• Stopkontak di kamar tamu longgar = natural, general, concise
• Stopkontaknya longgar = The outlet is loose
• Stopkontaknya di kamar tamu longgar could be understood, but word order may be less clear depending on context

Adding -nya often makes something sound more definite, like the specific outlet already known in context.

A very natural fuller version would be:

• Stopkontak di kamar tamu longgar; tolong periksa stopkontaknya dulu.

But the original sentence is perfectly normal because the outlet is already understood.

Yes. It is very natural Indonesian.

Indonesian often allows:

• no explicit is
• no explicit object when it is understood
• short, efficient statements

So the sentence is compact, but grammatically normal:

• Stopkontak di kamar tamu longgar = statement
• tolong periksa dulu = polite request

Together they form a very natural instruction/report style sentence.