Det ene glas står på bordet, og det andet står i skabet.

This is a very common Danish pattern for contrasting two items:

• det ene glas = the one glass
• det andet = the other one / the second one

So Danish is pairing two things and distinguishing them from each other.

A very common set of patterns is:

• den ene ... den anden ... for common gender nouns
• det ene ... det andet ... for neuter nouns

Here, glas is a neuter noun, so Danish uses det.

Because glas is a neuter noun in Danish.

Danish nouns have two grammatical genders:

• common gender → uses en, den
• neuter → uses et, det

Since the noun is et glas, the corresponding form here is det ene glas.

Compare:

• den ene stol, den anden stol = the one chair, the other chair
• det ene glas, det andet glas = the one glass, the other glass

Again, it is because glas is neuter.

The forms are:

• anden for common gender
• andet for neuter

So:

• den anden stol
• det andet glas

You can think of andet as the neuter form of anden.

Because after den ene / det ene / den anden / det andet, Danish normally uses the noun in its basic form, not with the attached definite ending.

So Danish says:

• det ene glas
• det andet glas

not:

• det ene glasset
• det andet glasset

This is similar to how some determiners in Danish already make the noun phrase definite enough, so the noun itself does not also take the definite ending.

But in på bordet and i skabet, there is no such determiner before the noun, so the definite ending appears directly on the noun:

• bordet = the table
• skabet = the cupboard / cabinet

Danish very often uses positional verbs where English simply uses is.

Here:

• står = stands
• ligger = lies
• sidder = sits

For many objects, Danish prefers one of these rather than er, especially when talking about location.

A glass is seen as an upright object, so Danish naturally says:

• Glasset står på bordet.

English would usually just say The glass is on the table, but Danish often prefers stands in this kind of sentence.

They use different prepositions because the locations are different in type:

• på bordet = on the table
  Use på for something on a surface.

• i skabet = in the cupboard/cabinet
  Use i for something inside an enclosed space.

So this is not just vocabulary; it is a very normal preposition choice in Danish:

• på = on
• i = in

That -et is the definite ending for many neuter nouns in Danish.

• et bord = a table

• bordet = the table

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

So instead of a separate word like English the, Danish often adds definiteness directly to the noun.

Because after og, Danish usually keeps normal main-clause word order unless something other than the subject comes first.

Normal word order is:

• subject + verb

So here:

• det andet = subject
• står = verb

That gives:

• og det andet står i skabet

You get inversion in Danish when another element is placed first, for example:

• I skabet står det andet glas.

There, I skabet comes first, so the verb står comes before the subject.

Usually, yes, or at least it strongly suggests a contrast between one and the other.

In many contexts it refers to two specific items:

• one glass is on the table
• the other glass is in the cupboard

Sometimes in broader contexts it can mean one ... another ..., but the most natural reading is that two glasses are being contrasted.

Yes, absolutely.

The second glas is often omitted because it is understood already:

• Det ene glas står på bordet, og det andet står i skabet.

This sounds natural and avoids repetition.

But you can also repeat the noun:

• Det ene glas står på bordet, og det andet glas står i skabet.

That is also grammatically correct.

In careful pronunciation, it is written det, but in normal speech it is often pronounced more like de or a reduced form, especially when unstressed.

So learners often notice that the written form and spoken form do not always match perfectly.

That is very normal in Danish. The spelling stays det, but the everyday pronunciation is often lighter than an English speaker expects.

Yes, very often.

For common gender nouns:

• Den ene bog ligger på stolen, og den anden ligger på bordet.

For neuter nouns:

• Det ene æble er rødt, og det andet er grønt.

So the key thing to learn is the pair:

• den ene / den anden
• det ene / det andet

and then choose the one that matches the noun’s gender.