Grillspyddet er langt.

Because Danish, like German, normally writes compound nouns as a single word.

So:

• grill
  • spyd → grillspyd

This is very common in Danish. English often uses separate words, but Danish usually joins them.

In Danish, the definite article is often added to the end of the noun instead of written as a separate word.

Here:

• grillspyd = skewer
• grillspyddet = the skewer

So the -et ending is doing the job of English the.

It is an et-word, which means it is a neuter noun.

That gives you forms like:

• et grillspyd = a skewer
• grillspyddet = the skewer

This also affects the adjective later in the sentence.

Because the adjective has to agree with the noun.

Since grillspyddet is:

• singular
• neuter
• and the adjective is used after er

the adjective takes -t:

• lang → common gender singular
• langt → neuter singular

So:

• En stol er lang would be wrong anyway because lang usually describes length, but grammatically lang is the common-gender form.
• Et bord er langt = correct neuter pattern
• Grillspyddet er langt follows that same pattern

Good question. In this sentence, the adjective is predicative, meaning it comes after er and describes the noun.

Predicative adjectives in Danish agree for:

• gender
• number

but not in the same way for definiteness as adjectives placed before a noun.

So:

• Grillspyddet er langt = correct
• not Grillspyddet er lange

Compare:

• et langt grillspyd = a long skewer
• det lange grillspyd = the long skewer
• grillspyddet er langt = the skewer is long

Er is the present tense of at være, which means to be.

So:

• at være = to be
• er = is / are / am, depending on context

In this sentence, it means is:

• Grillspyddet er langt = The skewer is long

The dictionary form is grillspyd.

If you want to look it up, you would usually search for the indefinite singular form:

• grillspyd

Then you can build other forms from it:

• et grillspyd
• grillspyddet

Because -et is the usual definite singular ending for many et-words.

So the pattern is:

• et grillspyd = a skewer
• grillspyddet = the skewer

That -et ending is one of the most important noun patterns in Danish.

Because the noun’s definite form is spelled grillspyddet in standard Danish. When endings are added, Danish spelling sometimes changes slightly rather than just adding letters in the simplest possible way.

For a learner, the important thing is to memorize the full form:

• grillspyd
• grillspyddet

It is best to learn the definite form together with the noun, especially when the spelling is not fully predictable.

No, this is the normal Danish statement pattern:

• Subject + verb + adjective/complement

So:

• Grillspyddet = subject
• er = verb
• langt = complement

This is very similar to English:

• The skewer is long

Yes. That is the natural form when the adjective comes before the noun.

• et langt grillspyd = a long skewer

Here the adjective lang still takes -t because grillspyd is a neuter noun.

If the noun is definite and the adjective comes before it, you would say:

• det lange grillspyd = the long skewer

So you can compare:

• et langt grillspyd
• det lange grillspyd
• grillspyddet er langt

Only because it is the first word of the sentence.

In Danish, nouns are not generally capitalized the way they are in German. So in the middle of a sentence, it would normally be written:

• grillspyddet

not with a capital letter.