Læsefeltet er lille.

Because Danish usually puts the definite article at the end of the noun.

• et felt = a field
• feltet = the field

Here, læsefeltet is a compound noun:

• læse = read / reading
• felt = field

So:

• læsefelt = reading field
• læsefeltet = the reading field

This is very common in Danish. Instead of a separate word like English the, Danish often adds -en or -et to the noun.

Because felt is a neuter noun in Danish.

Danish nouns have two grammatical genders:

• common gender → usually takes en
• neuter gender → usually takes et

So:

• et felt = a field
• feltet = the field

Since the main noun in the compound is felt, the whole compound follows that gender:

• et læsefelt
• læsefeltet

The last part of a compound usually determines the gender.

Because Danish, like German, often forms compound nouns as a single word.

So English might write something like:

• reading field

But Danish normally writes:

• læsefelt

This is very typical Danish spelling. The first part describes the second part, and they are joined into one noun.

Læse is the verb to read, but in compounds it often works like reading in English.

So læsefelt literally means something like:

• reading field
• field for reading
• reading area

In compounds, Danish often uses the bare verb form as the first element.

Compare the idea in English:

• swimming pool
• drinking water
• reading field

The first part helps describe the noun that follows.

Because lille is an irregular adjective.

With many Danish adjectives, the adjective changes for neuter singular:

• stor → stort
• lille bil / bilen er stor
• et stort hus / huset er stort

But lille is special. In normal modern Danish, lille is used for singular nouns of both genders, including neuter:

• en lille bil
• et lille hus
• bilen er lille
• huset er lille

So in your sentence:

• Læsefeltet er lille.

that is the normal correct form.

Yes, but in a slightly special way.

Danish adjectives often agree with the noun in gender and number. For example:

• en stor bil = a big car
• et stort hus = a big house
• husene er store = the houses are big

But lille is irregular:

• singular: lille
• plural: often små

So:

• læsefeltet er lille = the reading field is small
• læsefelterne er små = the reading fields are small

Er is the present tense of at være (to be).

So:

• er = is / are / am, depending on context

In this sentence:

• Læsefeltet er lille.
• The reading field is small.

Danish does not change the verb for different persons the way English does. Compare:

• jeg er = I am
• du er = you are
• det er = it is
• vi er = we are

The form stays er.

The structure is:

• Subject + verb + adjective

So:

• Læsefeltet = subject
• er = verb
• lille = adjective / subject complement

This is a very basic Danish sentence pattern, similar to English:

• The reading field is small.

Because after er (is), Danish often uses an adjective to describe the subject.

This works just like English:

• Bilen er stor. = The car is big.
• Huset er gammelt. = The house is old.
• Læsefeltet er lille. = The reading field is small.

The adjective is not directly before the noun here, because it is part of the predicate, not part of the noun phrase.

Compare:

• et lille læsefelt = a small reading field
• læsefeltet er lille = the reading field is small

Then the adjective would go before the noun.

• et lille læsefelt = a small reading field

But in your sentence, the noun is already definite and the adjective comes after er:

• læsefeltet er lille = the reading field is small

So the difference is:

• et lille læsefelt → adjective inside the noun phrase
• læsefeltet er lille → adjective after the verb, describing the subject

A learner will often notice two tricky parts:

1. æ in læse
2. the ending -et

A rough pronunciation guide is:

• læsefeltet ≈ LEH-seh-fel-ted
  or more naturally LEH-suh-fel-ted

A few notes:

• æ is a front vowel, somewhat like the vowel in English bed, though not exactly the same.
• The final -et in Danish often sounds more like -ed than a clear English -et.
• The e in unstressed syllables is often reduced.

If you are learning pronunciation, it helps to hear native audio, because Danish spelling and pronunciation are not always obvious.

Because in modern Danish, nouns are not capitalized.

So you write:

• Læsefeltet er lille.

not:

• Læsefeltet er Lille.
• Læsefeltet Er Lille.

Only the first word of the sentence is capitalized here because it begins the sentence, not because it is a noun.

This is different from German, where all nouns are capitalized.

Yes, but it means something different in structure.

• Det lille læsefelt = the small reading field

That is a noun phrase, not a full sentence.

Your original sentence is a complete sentence:

• Læsefeltet er lille. = The reading field is small.

Compare:

• det lille læsefelt = the small reading field
• læsefeltet er lille = the reading field is small

In the first one, lille is placed before the noun. In the second one, lille comes after er.

The plural would change both the noun and the adjective.

Likely:

• Læsefelterne er små. = The reading fields are small.

Here:

• læsefelterne = the reading fields
• små = small (plural form normally used with lille)

So this is a good contrast:

• Læsefeltet er lille. = The reading field is small.
• Læsefelterne er små. = The reading fields are small.