Glasaffaldet hører til i beholderen.

Glasaffaldet is a compound noun:

• glas = glass
• affald = waste, trash
• glasaffald = glass waste
• glasaffaldet = the glass waste

Danish very often combines nouns into one word, where English would often use two words.

The ending -et is the definite article attached to the noun, so it means the.

In Danish, instead of usually putting a separate word like the before the noun, you often add the definite ending directly to the noun:

• et glasaffald = a glass waste item / glass waste
• glasaffaldet = the glass waste

Here, affald is a neuter noun, so the definite ending is -et.

Compare:

• common gender: en beholder → beholderen
• neuter gender: et affald → affaldet

Høre til is a fixed expression. In this sentence it means something like:

• belongs in
• is supposed to go in
• goes in

So Glasaffaldet hører til i beholderen means that glass waste is the kind of thing that should be placed in that container.

This is not just the basic verb høre = to hear. With til, the meaning changes.

Examples:

• Det hører til her. = It belongs here.
• Skoene hører til under sengen. = The shoes belong under the bed.

By itself, høre usually means to hear. But in høre til, it is part of a different expression.

So:

• Jeg hører musik. = I hear/listen to music.
• Det hører til her. = It belongs here.

That is a very common thing in Danish: a verb plus a small word like til, op, ud, etc. can create a new meaning.

Hører is the present tense of høre til.

• infinitive: at høre til
• present: hører til

Danish often uses the present tense for general truths, instructions, and rules. So here it means something like:

• glass waste belongs in the container
• glass waste goes in the container

It is not talking about something happening only right now. It is a general statement.

They do different jobs here.

• til is part of the fixed expression høre til
• i is the normal preposition meaning in

So the sentence breaks down like this:

• glasaffaldet
• hører til
• i beholderen

You should think of høre til as one unit, and then i beholderen tells you where it belongs.

So the structure is closer to:

• The glass waste belongs
  • in the container

not:

• The glass waste hears to in the container

Beholder means container or bin, depending on context.

• en beholder = a container
• beholderen = the container

The ending -en is the definite article for a common gender noun.

So:

• en beholder → beholderen
• et glas → glasset

This is why the sentence has:

• glasaffaldet with -et
• beholderen with -en

They are different because the nouns have different grammatical gender.

Because Danish usually puts the at the end of the noun as a suffix.

So instead of saying:

• the container

Danish usually says:

• beholderen

And instead of:

• the glass waste

Danish says:

• glasaffaldet

This is one of the biggest structural differences from English.

The sentence uses normal, neutral Danish word order:

• Glasaffaldet = subject
• hører til = verb
• i beholderen = prepositional phrase

So the pattern is basically:

• Subject + verb + place

Very natural for a simple statement.

Danish is a V2 language, which means the finite verb is usually in second position in main clauses. In this sentence, that rule is followed normally:

• Glasaffaldet | hører | til i beholderen

Yes. A few alternatives are possible, but they are not exactly identical in tone.

For example:

• Glasaffald skal i beholderen.
  = Glass waste must/goes in the container.
  This sounds a bit more direct or instructional.

• Glasaffaldet skal i beholderen.
  = The glass waste must go in the container.

• Glasaffald hører til i beholderen.
  = Glass waste belongs in the container.
  This can sound more general.

Using hører til often gives the sense of this is the proper place for it.

Both are possible in Danish, but they differ slightly in feel.

• glasaffald = glass waste in a general sense
• glasaffaldet = the glass waste, or the glass waste being referred to in the situation

On a sign or sorting instruction, Danish may use either the definite or indefinite form depending on style. The definite form can sound like it refers to the category of waste you are dealing with right there.

So this sentence feels like:

• The glass waste belongs in the container

meaning the glass waste in question should go there.

Very roughly for an English speaker:

• hører sounds something like HUH-rer or HER-rer, but with Danish vowels that do not match English exactly
• til sounds roughly like teel with a short, light i

A few helpful points:

• the ø sound in hører is not an English vowel
• the final r in Danish is usually softer than in many English accents
• in natural speech, hører til may sound more connected and less sharply separated than the spelling suggests

If you are learning pronunciation, ø is one of the sounds worth practicing early.

Here it is best understood as an uncountable/mass noun, like waste in English.

So glasaffald means glass waste as a category or substance, not glass wastes as separate countable items.

That is why the English translation is usually not something like the glass wastes. It is simply the glass waste or more naturally glass waste.