Hageslangen er lang.

Because Norwegian very often makes compound nouns by writing them as a single word.

• hage = garden
• slange = hose / snake, depending on context

So:

• hageslange = garden hose

This is extremely common in Norwegian. Where English often uses two words, Norwegian often uses one compound word.

The ending -en is the definite article attached to the noun. It corresponds to English the.

So:

• en hageslange = a garden hose
• hageslangen = the garden hose

This is a very important feature of Norwegian: instead of putting the in front, Norwegian often puts definiteness on the end of the noun.

Because Norwegian usually marks definiteness with a suffix, not a separate article.

So English says:

• the garden hose

But Norwegian says:

• hageslangen

The -en already means the, so you do not need another word before it in this sentence.

A separate word like den is used in other situations, for example:

• den lange hageslangen = the long garden hose

There, den appears because there is an adjective directly before the noun.

It is singular definite.

Breakdown:

• hageslange = singular indefinite, a garden hose
• hageslangen = singular definite, the garden hose
• hageslanger = plural indefinite, garden hoses
• hageslangene = plural definite, the garden hoses

So in your sentence, the subject is one specific garden hose.

Er is the present tense of å være = to be.

So:

• jeg er = I am
• du er = you are
• han/hun er = he/she is
• den er = it is

In this sentence, er links the subject and the description:

• Hageslangen = the garden hose
• er = is
• lang = long

This is a very basic Norwegian sentence pattern:

subject + er + adjective

For example:

• Bilen er stor. = The car is big.
• Kaffen er varm. = The coffee is hot.

Because it agrees with the noun in the way Norwegian requires for a predicative adjective.

Here, lang comes after er, so it is a predicative adjective, not one placed directly before the noun.

With a common-gender singular subject like hageslangen, the normal form is:

• lang

Compare:

• Hageslangen er lang. = The garden hose is long.
• Tauet er langt. = The rope is long.
  (tauet is neuter, so the adjective becomes langt.)
• Hageslangene er lange. = The garden hoses are long.
  (plural gives lange)

So lang is correct because hageslangen is singular and not neuter.

It is a common gender noun, which is why the indefinite article is en:

• en hageslange = a garden hose

That also helps explain the adjective form in sentences like this:

• Hageslangen er lang.

If it were a neuter noun, you would expect the adjective to look different, often with -t in this kind of sentence.

No. They are related in meaning, but they are used differently.

• lang = long, used for length/size
• lenge = for a long time, used for duration

So here:

• Hageslangen er lang. = The garden hose is long.
  This is about physical length.

But:

• Jeg ventet lenge. = I waited a long time.
  This is about time.

English speakers often mix these up at first, so it is a useful distinction to remember.

Yes. Slange can mean snake, but in compounds and everyday context it can also refer to something long and flexible, such as a hose.

So:

• en slange can mean a snake
• en hageslange clearly means a garden hose

The first part of the compound usually makes the meaning clear.

A helpful approximate pronunciation for an English speaker is:

HAH-guh-slang-en

A few notes:

• hage sounds roughly like HAH-guh
• slangen begins with sl-, which is pronounced normally
• the g in hage is pronounced here, unlike in some other Norwegian words where letters may weaken or disappear
• the stress is mainly on the first part of the compound: HA-geslangen

Exact pronunciation varies by dialect, but that approximation will usually be understood.

It would be:

• En hageslange er lang.

That means A garden hose is long or A garden hose is long in general, depending on context.

Compare:

• Hageslangen er lang. = The garden hose is long.
• En hageslange er lang. = A garden hose is long.

So the difference is mainly definite versus indefinite.

Because this is a very straightforward declarative sentence, and Norwegian often matches English word order in simple statements.

Pattern:

• Subject: Hageslangen
• Verb: er
• Adjective/complement: lang

So both languages use:

The garden hose + is + long

This similarity makes sentences like this easy for English speakers, even though the noun form itself works differently because of the definite ending -en.

Usually, not as the normal neutral version of this sentence.

If you just want to say The garden hose is long, the natural form is:

• Hageslangen er lang.

Using den before a definite noun usually changes the meaning or adds special emphasis, and in many cases it sounds unnatural unless the structure specifically calls for it.

However, if you add an adjective before the noun, then Norwegian normally uses double definiteness:

• Den lange hageslangen er dyr. = The long garden hose is expensive.

So for your exact sentence, Hageslangen er lang is the standard form.