Det farlige affald er i skabet.

Because affald is a neuter noun in Danish, and when a definite noun phrase has an adjective before the noun, Danish uses det for neuter singular.

So:

• et affald = a waste material / waste
• det farlige affald = the dangerous waste

Compare:

• den røde bil = the red car
• det røde hus = the red house
• de røde biler = the red cars

So det here does not mean it. It is the definite article used with a neuter noun phrase.

Because adjectives in Danish usually take -e when they are used in a definite noun phrase.

Here, farlige describes affald, and the whole phrase is definite: det farlige affald.

Compare:

• farligt affald = dangerous waste
• det farlige affald = the dangerous waste

A quick pattern:

• en farlig hund = a dangerous dog
• et farligt stof = a dangerous substance
• de farlige hunde = the dangerous dogs
• det farlige stof = the dangerous substance

So the -e in farlige is there because the noun phrase is definite.

This is a very common learner question.

In standard Danish, when you have:

• a definite article like den, det, or de
• plus an adjective
• plus a noun

the noun usually stays in its indefinite form.

So:

• det farlige affald = correct
• det farlige affaldet = not standard Danish

Compare:

• huset = the house
• det store hus = the big house

Not:

• det store huset

This is an important difference from English and also from some other Scandinavian patterns learners may have seen.

You usually learn a Danish noun together with its indefinite article:

• en
  • noun
• et
  • noun

For this word, it is:

• et affald

That tells you it is neuter, which is why the sentence uses det in the definite phrase.

In practice, you often need to memorize noun gender word by word, because it is not always predictable from meaning or spelling.

Because skabet is the definite singular form of skab.

• et skab = a cabinet / a cupboard
• skabet = the cabinet / the cupboard

For many neuter nouns, the definite singular ending is -et.

So:

• et hus → huset
• et skab → skabet
• et bord → bordet

That is why the sentence says i skabet = in the cupboard / in the cabinet.

Because Danish usually marks definiteness in one of two main ways:

1. Suffix on the noun when there is no adjective

   • skabet = the cupboard

2. Separate article + adjective + bare noun when there is an adjective

   • det store skab = the big cupboard

So:

• i skabet = in the cupboard
• i det store skab = in the big cupboard

That is why skabet can stand alone without det, but if you add an adjective, you normally use det and remove the noun’s definite ending.

Because this is normal Danish sentence structure.

The sentence is:

• Det farlige affald = subject
• er = verb
• i skabet = adverbial / prepositional phrase

In a normal main clause, Danish follows the verb-second rule, often called V2. That means the finite verb comes in the second position of the clause.

Here the subject phrase Det farlige affald takes the first position, so er comes second:

• Det farlige affald | er | i skabet

This is the standard word order for a simple statement.

Because i means in or inside, which fits the idea of something being inside a cupboard or cabinet.

So:

• i skabet = in the cupboard

Compare:

• på skabet = on the cupboard
• under skabet = under the cupboard
• ved skabet = by the cupboard

English speakers often need to pay close attention to Danish prepositions, because they do not always match English perfectly, but here i works just like in.

Yes. Affald is often used as a mass noun, much like waste or trash in English.

So in this sentence, it is grammatically singular:

• affald er = waste is

Even though it may refer to a quantity of material rather than one single object, Danish still treats it as a singular mass noun here.

That is why you get:

• Det farlige affald er i skabet.

not:

• Det farlige affald er i skabene. unless you mean the waste is in the cupboards
• Det farlige affald er ... with a plural verb, because Danish does not change the verb for singular/plural in the present tense anyway

A careful approximation is:

deh FAR-li-uh AH-fal air ee SKA-beth

A few helpful notes:

• det is often pronounced more like deh in connected speech
• farlige is often said roughly like FAR-li-uh
• affald has stress on the first syllable: AH-fald
• er is often a light vowel-like sound in normal speech
• skabet has stress on ska-

Natural Danish pronunciation is often much softer and more reduced than the spelling suggests, so listening to native audio is especially important for a sentence like this.