Jangan letak telefon dekat singki supaya tidak kena air.

Jangan is the normal word used to make a negative command in Malay.

So:

• Letak telefon dekat singki. = Put the phone near the sink.
• Jangan letak telefon dekat singki. = Don’t put the phone near the sink.

English uses don’t + verb. Malay usually uses jangan + verb for this kind of warning or instruction.

In Malay, jangan is specifically used for prohibitions or negative imperatives.

• jangan = don’t...
• tidak / tak = not

So if you want to tell someone not to do something, you normally use jangan.

Examples:

• Jangan duduk di situ. = Don’t sit there.
• Jangan makan itu. = Don’t eat that.

By contrast, tidak and tak usually negate statements, not commands:

• Saya tidak faham. = I do not understand.
• Telefon itu tidak mahal. = That phone is not expensive.

Yes. Letak commonly means put, place, or set down.

In everyday Malay, letak is very common and natural:

• Letak buku atas meja. = Put the book on the table.
• Dia letak beg di kerusi. = He/She put the bag on the chair.

In this sentence, jangan letak telefon... means don’t put the phone...

Malay does not use articles like a, an, or the the way English does.

So:

• telefon can mean a phone, the phone, or just phone
• singki can mean a sink or the sink

The exact meaning depends on context.

That means jangan letak telefon dekat singki could naturally be understood as:

• Don’t put the phone near the sink
• Don’t put a phone near a sink

In real use, context tells you which one is meant.

Here, dekat means near or close to.

So:

• dekat singki = near the sink

Dekat is very common in spoken and everyday Malay for location.

Examples:

• Rumah saya dekat sekolah. = My house is near the school.
• Kedai itu dekat sini. = That shop is near here.

In some contexts, dekat can also mean at in casual usage, but in this sentence near is the best meaning.

Yes—it's a commonly used Malay word, borrowed from English sink.

Malay has many loanwords, especially for modern objects and household items. Singki is widely understood in everyday speech.

You may also notice that the spelling has been adapted to Malay pronunciation:

• English: sink
• Malay: singki

This kind of borrowing is very normal in Malay.

Supaya means so that, in order that, or so that ... not depending on the sentence.

In your example:

• supaya tidak kena air = so that it doesn’t get water on it / so that it won’t be exposed to water

So the whole sentence is structured like this:

• Jangan letak telefon dekat singki = Don’t put the phone near the sink
• supaya tidak kena air = so that it doesn’t get wet / so that water doesn’t get on it

It introduces the purpose or reason for the instruction.

Because tidak negates the phrase.

• kena air = get hit by water / get water on it / be exposed to water
• tidak kena air = not get water on it

So:

• supaya tidak kena air = so that it does not get water on it

This is different from the first part of the sentence, where the speaker is giving a command and so uses jangan. Inside the supaya clause, it is not a command anymore—it is describing the desired result, so tidak is correct there.

Literally, kena often means something like be hit by, be affected by, or come into contact with.

So kena air literally suggests get hit by water or be affected by water.

In natural English, you would usually translate it more smoothly as:

• get wet
• get water on it
• be exposed to water

This is a very useful Malay pattern:

• kena hujan = get rained on
• kena panas = be exposed to heat
• kena marah = get scolded
• kena tipu = get tricked

So kena is a flexible and common word in Malay.

Malay often leaves out subjects when they are already clear from context.

In this sentence, the thing that would kena air is obviously telefon, so there is no need to repeat it.

English usually needs the subject:

• so that it doesn’t get wet

Malay can simply say:

• supaya tidak kena air

This kind of omission is very common and natural in Malay.

Yes. Agar and supaya are both used to mean so that.

So you could say:

• Jangan letak telefon dekat singki agar tidak kena air.

That said, supaya is often felt to be a little more common in everyday speech, while agar can sound slightly more formal or written, depending on context. Both are correct.

Yes, it is natural and understandable. A native speaker might also say it in slightly different ways, for example:

• Jangan letak telefon dekat singki, nanti kena air. = Don’t put the phone near the sink, or it’ll get water on it.

• Jangan letak telefon dekat singki supaya telefon itu tidak kena air. = Don’t put the phone near the sink so that the phone doesn’t get wet.
  This is grammatical, but repeating telefon itu is less necessary.

• Jangan letak telefon dekat singki, takut kena air. = Don’t put the phone near the sink, in case it gets wet.

Your original sentence is perfectly fine, especially as a clear instructional sentence.

Yes. Telefon just means telephone/phone, while telefon bimbit specifically means mobile phone or cell phone.

So if you want to be more specific, you can say:

• Jangan letak telefon bimbit dekat singki supaya tidak kena air.

In everyday modern usage, though, telefon is often enough if the context already makes it clear that you mean a mobile phone.