Tolong isi gelas ini dengan air.

Please fill this glass with water.

Breakdown of Tolong isi gelas ini dengan air.

• ini: this
• dengan: with
• tolong: please
• air: the water
• gelas: the glass
• isi: to fill

Questions & Answers about Tolong isi gelas ini dengan air.

What does the word “tolong” do here? Is it just “please”?

• Tolong literally means “help,” but before a verb it functions like “please” in requests: Tolong isi… = “Please (help to) fill…”
• Politeness: It’s neutral–polite in everyday speech. Softer variants include:
  • Bisa tolong…? / Boleh tolong…? = “Could you…?”
  • Tolong …, ya. adds a gentle tone.
  • More formal: Mohon…, Harap…, Silakan… (context-dependent; see below).
• Shouted alone (Tolong!) means “Help!”

Why is it “isi” and not “mengisi”?

• Indonesian imperatives typically use the bare verb root: isi (fill), buka (open), tutup (close).
• Mengisi is the active non-imperative form: Saya mengisi gelas ini dengan air (“I fill this glass with water”).
• You can soften an imperative with -lah: Isilah gelas ini… (more polite/formal).
• You may also see isikan, which adds -kan (often benefactive or making it sound more service-oriented): Isikan gelas ini dengan air.

Can I say “Tolong mengisi gelas ini dengan air”?

• It’s grammatical and you will hear/read it, but in conversation Tolong isi… is more direct and natural.
• In notices/instructions, you’ll often see:
  • Mohon mengisi… or Harap mengisi… (formal written requests).
  • Service style: Tolong diisi… (passive; avoids saying “you”).

What does “dengan” mean here? Could I leave it out?

• Dengan = “with/using.” It marks the instrument/substance: isi … dengan air = “fill … with water.”
• You can omit it if the substance is obvious from context: Tolong isi gelas ini (implies “with water” if that’s understood).
• Alternatives:
  • pakai or menggunakan (“use”): Isi gelas ini pakai air.
  • If you’re emphasizing direction into something, use ke (dalam) with a pouring verb: Tuangkan air ke dalam gelas ini (“Pour water into this glass”).

Why is it “gelas ini” and not “ini gelas”?

• When “this/that” modifies a noun, it follows the noun: gelas ini (“this glass”), gelas itu (“that glass”).
• Ini gelas means “This is a glass” (a full sentence: demonstrative + noun).

Does Indonesian need articles like “a/the”? Is there a plural?

• No articles. Gelas can mean “a glass” or “the glass” depending on context.
• To be specific, you can use ini/itu or -nya: gelas ini (this glass), gelasnya (the glass/its glass).
• Plural can be left unmarked or shown with context, reduplication, or quantifiers:
  • gelas-gelas, beberapa gelas (several glasses), dua gelas (two glasses).

Is “air” a false friend with English “air”? How do I pronounce it?

• Yes, air in Indonesian means “water.” Pronunciation: two syllables, “ah-eer” [a.ir].
• Other pronunciations:
  • tolong: TO-long, final ng = [ŋ], as in “sing.”
  • dengan: də-NGAN (first e is schwa [ə]).
  • gelas: gə-LAS (first e is schwa).
  • isi: EE-see.
  • r in Indonesian is tapped/trilled, not the English “r.”

Would “air putih” be better than just “air”?

• In everyday Indonesian, air putih (“plain/clear water”) commonly means drinking water. If you want to be explicit about drinking water, you can say:
  • Tolong isi gelas ini dengan air putih.
• Air alone is still fine and understood as “water” unless there’s ambiguity (e.g., juice, milk also available).

What’s the difference between “gelas” and “cangkir”?

• gelas: a tumbler/glass (often tall, no handle), any material; also generic “drinking glass.”
• cangkir: a cup, typically with a handle (tea/coffee cup), usually ceramic.

How do I make the request softer or more service-like?

• Add softeners:
  • Tolong isi gelas ini dengan air, ya.
  • Bisa tolong isi gelas ini dengan air?
  • Tolong isikan gelas ini dengan air. (with -kan)
• Passive to sound less direct (common to staff):
  
  • Tolong gelas ini diisi dengan air.
  • Bisa diisi gelasnya dengan air?

Is “isi” ever a noun?

• Yes. isi as a noun = “content(s).”
  • isi gelas = the contents of the glass.
  • As a verb here, context and position after tolong show it means “fill.”

Could I say “Tolong tuangkan air ke gelas ini” instead?

• Yes. Tuangkan = “pour (something).”
  
  • Tolong tuangkan air ke dalam gelas ini emphasizes the action of pouring into.
  • Isi … dengan … emphasizes making the container full with a substance.

Is “dengan air” redundant if we obviously mean water?

• If the only reasonable liquid is water, you can drop it: Tolong isi gelas ini.
• If multiple liquids are possible, keep it: … dengan air / dengan teh / dengan susu. You can specify temperature: air hangat, air dingin, air panas.

Are there very formal alternatives?

• On signs/emails/forms:
  • Mohon isi/mengisi… (respectful/formal)
  • Harap isi/mengisi… (please be advised to…)
  • Silakan isi… (you are welcome/please go ahead to fill…)
• For staff instructions, passive is common: Gelas ini harap diisi dengan air.

Can I change the word order to put “air” first?

• Yes, if you use a verb that selects direction into the container:
  • Tuangkan air ke (dalam) gelas ini.
• With isi, keep the container as the object and the substance after dengan:
  • ✓ Isi gelas ini dengan air.
  • ✗ Isi air gelas ini (ungrammatical/awkward in this meaning).

How would I say “a glass of water”?

• Use a classifier-like construction: segelas air = “a glass of water.”
• Plurals/quantities: dua gelas air (two glasses of water), beberapa gelas air (several glasses of water).