Learn Hardcore Indonesian: Sumur itu sangat dalam.

Sumur is most commonly a water well (a hole dug in the ground to get water).
It usually refers to a man‑made well, not a natural spring or pond.
Other water sources have different words, like mata air (spring) or kolam (pond/pool), so sumur is specifically the kind of well you draw water from with a bucket or pump.

Why is there no word for is in Sumur itu sangat dalam?

In Indonesian, when you link a noun to an adjective, you usually don’t use a verb like “is/are”.
So Sumur itu sangat dalam literally feels like “That well very deep”, but it’s perfectly correct and natural.
A linking verb like adalah is mostly used before nouns or long explanations, not before adjectives like dalam.

What does itu do here? Is it that or the?

Itu literally means that, but in real usage it often works like the in English.
So sumur itu can mean that well (specific, maybe visible or known) or more loosely the well (a particular one already in the context).
The demonstrative comes after the noun in Indonesian (sumur itu, not itu sumur in this kind of sentence).

Can I drop itu and just say Sumur sangat dalam?

You can say Sumur sangat dalam, but it sounds a bit odd or incomplete in most everyday contexts.
Without itu (or some other determiner), sumur feels more like “wells (in general) are very deep”, or like a heading/title, not a normal specific statement.
If you want to talk about a specific well, use sumur itu; if you really mean wells in general, you could say Sumur biasanya dalam (Wells are usually deep).

Why is the order sumur itu and not itu sumur?

With nouns, Indonesian usually puts the demonstrative after the noun:

sumur itu = that well
buku ini = this book

The pattern is noun + ini/itu.
Itu sumur can exist, but it has a different feel, more like “That’s a well” in a pointing/identifying sentence, and you would normally add adalah or a pause: Itu (adalah) sumur.

Why does the adjective dalam come after the noun, not before like in English?

In Indonesian, adjectives almost always come after the noun:

sumur dalam = deep well
rumah besar = big house
air panas = hot water

So if you say Sumur itu sangat dalam, it literally follows the pattern [noun] [demonstrative] [degree word] [adjective].
Putting dalam before sumur would be ungrammatical.

What is the role of sangat here? How strong is it?

Sangat means very and is a neutral, standard, and a bit formal way to intensify an adjective.
So sangat dalam = very deep.
It’s stronger than just dalam (deep) but not exaggerated like extremely or sooooo deep in English; it’s a normal, serious emphasis.

Can sangat go after dalam, like dalam sangat?

No, sangat always comes before the adjective: sangat dalam, sangat besar, etc.
If you want something after the adjective, you can use sekali:

dalam sekali = very deep (literally: deep once/one‑time, but used as an intensifier)
So:
sangat dalam = very deep (neutral/standard)
dalam sekali = very deep (also common, a bit more casual in feel).

What’s the difference between sangat dalam, dalam sekali, and dalam banget?

sangat dalam – standard, neutral, can be used in formal writing and speech.
dalam sekali – common in everyday speech and writing, still acceptable in formal contexts.
dalam banget – informal/slang, used in casual spoken Indonesian, especially in Jakarta style; avoid this in formal writing or with people you must speak politely to.
All three mean roughly very deep, but they differ in formality and tone.

Could Sumur itu sangat dalam ever mean “The wells are very deep” (plural)?

Yes, Indonesian does not mark plural on nouns by default, so sumur itu can mean either “that well / the well” (singular) or “those wells / the wells” (plural), depending on context.
If you want to make the plural clear, you can say sumur‑sumur itu (those wells) or add a number or word like banyak (many): banyak sumur itu sangat dalam (many of those wells are very deep).
Without extra words, listeners rely on the situation to know whether it’s singular or plural.

Is Sumur itu sangat dalam formal, informal, or neutral?

The sentence is neutral.
The vocabulary (sumur, itu, sangat, dalam) is standard and can be used in both spoken and written Indonesian.
In very casual speech, someone might shorten or change the intensifier (for example dalam banget), but Sumur itu sangat dalam is safe in almost any context.

How do you pronounce sumur and dalam correctly?

sumur: su-mur
- su like soo in soon
- mur like moor (but with a tapped/flapped r in many accents)
dalam: da-lam
- da like da in darling
- lam like lum in lumber, but with a clearer a sound

Stress is usually on the first syllable: SUmur, DAlam, but Indonesian stress is softer and less dramatic than in English.

Is there a related noun like “depth” in Indonesian?

Yes, the related abstract noun is kedalaman, which means depth.
For example:

Kedalaman sumur itu 20 meter. = The depth of that well is 20 meters.
So dalam = deep (adjective), kedalaman = depth (noun).