Learn Hardcore Indonesian: Peraturan itu menjelaskan bahwa masker perlu dipakai dan ponsel perlu dimatikan selama konsultasi. - Those rules explain that masks need to be worn and phones need to be turned off during the consultation.

Itu literally means “that”, but in this context it works like the English definite article “the”:
peraturan itu ≈ that rule / the rule (a specific rule already known from context).

With itu: you’re referring to a particular rule that has been mentioned or is obvious from context.
Without itu (peraturan menjelaskan bahwa…): this sounds more general or abstract, like “a rule” or “rules in general” explain that…

So you can leave itu out, but the nuance changes slightly from “that specific rule” to something more general.

Why do we use menjelaskan bahwa instead of just stating the rule directly?

Menjelaskan bahwa means “explains that…” and introduces an explanation or content of a rule, statement, or text.

Structure:

peraturan itu menjelaskan bahwa …
= that rule explains that …

Common similar patterns:

dokter itu menjelaskan bahwa… – the doctor explains that…
laporan ini menjelaskan bahwa… – this report explains that…

You could say the sentence more directly, for example:

Menurut peraturan, masker perlu dipakai dan ponsel perlu dimatikan selama konsultasi.
(According to the rules, masks need to be worn and phones need to be switched off during the consultation.)

But menjelaskan bahwa is natural when you frame the sentence as “The rule explains that…”.

What is the function of bahwa here? Is it necessary?

Bahwa functions like the English word “that” introducing a clause:

peraturan itu menjelaskan bahwa [masker perlu dipakai…]
= the rule explains that [masks need to be worn…]

In spoken Indonesian, bahwa is often dropped, especially in casual speech:

Peraturan itu menjelaskan masker perlu dipakai dan ponsel perlu dimatikan selama konsultasi.

This is still understandable and often heard, but in formal or written Indonesian, including bahwa is more standard and clear.

Why is it perlu dipakai and perlu dimatikan, not perlu memakai or perlu mematikan?

The pattern used here is:

perlu + passive verb (di- + verb)

This pattern focuses on the action that must happen rather than on who does it:

masker perlu dipakai
literally: “the mask(s) need to be worn”
focus: wearing needs to happen
ponsel perlu dimatikan
literally: “the phone(s) need to be turned off”

If you say perlu memakai masker, you are saying “(someone) needs to wear a mask” and you’re focusing more on the person who needs to do it. For example:

Anda perlu memakai masker. – You need to wear a mask.

In a rule written in a neutral, impersonal way, perlu dipakai / perlu dimatikan (passive) is more natural and formal.

Why use the passive dipakai / dimatikan instead of active forms like memakai / mematikan?

Indonesian often uses the passive voice in rules, instructions, and formal notices, because:

It sounds more impersonal and neutral, not aimed at a specific “you” or “they”.
It focuses on what must happen, not on who does it.

Compare:

Masker perlu dipakai. – Masks need to be worn. (impersonal, formal)
Anda perlu memakai masker. – You need to wear a mask. (directed at “you”)

Both are correct, but for a written regulation, the passive is more typical.

Could we say perlu untuk dipakai instead of perlu dipakai?

You can say perlu untuk dipakai, but in many cases untuk is unnecessary and makes the sentence heavier.

Natural usage:

Most common and simple: masker perlu dipakai
Possible but more wordy: masker perlu untuk dipakai

In formal writing, both can appear, but perlu + passive verb (without untuk) is usually preferred for being cleaner and more concise.

Why is perlu repeated: masker perlu dipakai dan ponsel perlu dimatikan? Can it be omitted in the second part?

It is natural to repeat perlu to keep the sentence clear:

masker perlu dipakai dan ponsel perlu dimatikan

You can omit the second perlu in speech:

Masker perlu dipakai dan ponsel dimatikan selama konsultasi.

This is understandable and can sound more casual. However, in formal writing, repeating perlu keeps the structure clearer and more balanced.

What does selama mean in selama konsultasi, and how is it different from saat or ketika?

Selama means “for the duration of / during (a period of time)”.

selama konsultasi = for the whole time of the consultation / during the consultation (from start to finish).

Differences:

selama – emphasizes the entire duration of a time period.
saat / ketika – more like “when” or “at the time (that)”, may refer to a moment or a more loosely defined time.

In a rule like this, selama konsultasi is ideal because the rule applies throughout the whole consultation, not just at one moment.

Why is there no plural marker for masker and ponsel even though the English translation uses plurals (“masks”, “phones”)?

Indonesian usually does not mark plural explicitly if it’s already clear from context.

masker can mean a mask or masks.
ponsel can mean a phone or phones.

Here, because we are talking about a general rule in a place where many people come for consultations, it naturally implies plural in English:

masker → “masks”
ponsel → “phones”

If you really need to emphasize plurality, you could say masker-masker or ponsel-ponsel, but in rules like this that’s usually unnecessary and sounds less natural.

What is the difference between peraturan and aturan? Could we say aturan itu instead?

Both peraturan and aturan come from the root atur (to arrange/regulate), and both can mean “rule(s), regulation(s)”.

peraturan: sounds more formal and is very common in official, legal, or institutional contexts.
aturan: slightly less formal, used both in everyday speech and writing.

So yes, you could say:

Aturan itu menjelaskan bahwa…

It would still be correct, just a bit more neutral or informal than peraturan in some contexts.

What does ponsel mean exactly, and are there more common words for “mobile phone” in Indonesian?

Ponsel is short for telepon seluler, meaning “cell phone / mobile phone”. It is quite standard and neutral.

Other common words:

HP (pronounced ha-pe) – very common in everyday speech, from handphone.
telepon genggam – literally “hand-held phone”, more formal or descriptive.

In a formal written rule, ponsel or telepon seluler are more likely; in casual conversation, HP is extremely common.