Sprekken er liten.

Because Norwegian usually marks definiteness by adding an ending to the noun.

• sprekk = crack / a crack (dictionary form)
• sprekken = the crack

So -en here is the definite ending. Norwegian often uses an ending where English uses a separate word like the.

In Bokmål, sprekk is commonly treated as a masculine noun in sentences like this, which is why the definite form is sprekken.

That matters because noun gender affects:

• the article
• the definite ending
• sometimes the form of adjectives

For example:

• en sprekk = a crack
• sprekken = the crack

You may also see feminine patterns with some nouns in Bokmål, but in this sentence the form used is clearly the masculine/common-gender definite form -en.

Because Norwegian usually builds the into the noun itself.

English:

• the crack

Norwegian:

• sprekken

So the sentence does not need a separate word like English the. The ending -en already does that job.

Because liten is the correct form for a singular masculine or feminine noun when the adjective comes after the verb, as it does here.

In Sprekken er liten:

• sprekken is singular
• it is not neuter
• the adjective is used predicatively (after er), not directly before the noun

Compare:

• en liten sprekk = a small crack
• sprekken er liten = the crack is small
• et lite hull = a small hole (lite because hull is neuter)
• den lille sprekken = the small crack (lille when the adjective comes before a definite noun)

So:

• liten = singular masculine/feminine
• lite = singular neuter
• lille = usually before a definite noun

Because that would be a different structure.

• den lille sprekken = the small crack
  This is a noun phrase, not a full sentence.

• Sprekken er liten = The crack is small
  This is a full sentence.

In other words:

• den lille sprekken describes the noun directly
• er liten tells you something about the noun

Er means is. It is the present tense of the verb å være (to be).

Examples:

• jeg er = I am
• du er = you are
• han er = he is
• sprekken er liten = the crack is small

This sentence has the normal word order for a simple Norwegian statement:

• Sprekken = subject
• er = verb
• liten = adjective describing the subject

So it follows the common pattern:

subject + verb + complement

That makes it very similar to English:

• The crack is small

Grammatically, yes, but it would usually mean something more general, like A crack is small, which often sounds strange or incomplete unless there is some larger context.

Compare:

• Sprekken er liten = The crack is small
  Refers to a specific crack.

• En sprekk er liten = A crack is small
  More general, and less natural in many situations.

So the definite form is usually the more natural choice when you are talking about one particular crack.

This is a very common confusion.

• liten means small
• smal means narrow

So if you are talking about overall size, liten is the right choice:

• Sprekken er liten = The crack is small

If you said Sprekken er smal, that would mean:

• The crack is narrow

That is possible, but it is a different idea.

A helpful approximate guide is:

SPREK-ken

A few points:

• the r is pronounced clearly in Norwegian
• the kk makes the consonant sound short and strong
• the ending -en is an unstressed definite ending

The exact pronunciation depends a bit on dialect, but for a learner it is enough to remember that it has two syllables:

• sprekk-en

Usually it refers to a crack, split, or fissure, often something physical in a wall, surface, object, and so on.

In the sentence Sprekken er liten, the most natural interpretation is a physical crack. Without more context, that is what most learners should assume.