Købsdatoen står på kvitteringen.

Because Danish normally writes compound nouns as one word.

So:

• køb = purchase / buy
• dato = date
• købsdato = purchase date

Then -en is added to make it definite:

• købsdato = a purchase date
• købsdatoen = the purchase date

This is very common in Danish. Where English often uses two words, Danish often uses one compound word.

The -s- is a linking sound/letter used in some Danish compounds.

Here:

• køb
  • dato becomes købsdato

That s does not usually add a separate meaning by itself. It just helps connect the parts of the compound in the natural Danish form.

You will see this in many Danish compound nouns, but not in all of them.

In Danish, the definite article is often attached to the end of the noun instead of being a separate word like the in English.

So:

• en kvittering = a receipt
• kvitteringen = the receipt

and:

• en købsdato = a purchase date
• købsdatoen = the purchase date

So both nouns in this sentence are definite.

Yes, stå literally means to stand, but Danish also uses it very naturally for written information appearing on something.

So in a sentence like this, står means something like:

• is written
• appears
• is listed

That is why Købsdatoen står på kvitteringen means that the purchase date is written on the receipt.

This use is extremely common in Danish. For example:

• Det står i bogen. = It says/is written in the book.
• Prisen står på pakken. = The price is written on the package.

Yes, it would be understandable, but står på kvitteringen is more natural if you are talking about text or printed information.

Compare:

• står på kvitteringen = is written on the receipt
• er på kvitteringen = is on the receipt

The version with er is more general. The version with står specifically suggests that the information is printed or written there.

Because the information is thought of as being on the surface of the receipt.

In Danish, as in English, written text is usually:

• på papiret = on the paper
• på skiltet = on the sign
• på kvitteringen = on the receipt

Using i would sound strange here, because the receipt is not being treated as a container.

Because in Danish, the usual way to say the with a noun is to add the definite ending directly to the noun:

• datoen = the date
• kvitteringen = the receipt

A separate word like den is often used when there is an adjective:

• købsdatoen = the purchase date
• den korrekte købsdato = the correct purchase date

So in this sentence, no separate the is needed.

The basic structure is:

• Købsdatoen = subject
• står = verb
• på kvitteringen = prepositional phrase

So it follows a normal simple Danish pattern:

Subject + verb + other information

That makes this sentence very straightforward grammatically.

Usually, yes. En kvittering is the normal Danish word for a receipt, especially proof of purchase from a shop.

So:

• på kvitteringen = on the receipt

Depending on context, English may also use sales receipt or till receipt, but kvittering is the standard everyday word.

A few helpful points:

• å in står is pronounced somewhat like the vowel in British English law or more, though not exactly the same.
• ø in købsdatoen is a rounded vowel that English does not really have. It is one of the sounds English speakers often need to practice separately.
• The g in -ingen in kvitteringen is not pronounced like a hard English g.

You do not need perfect pronunciation immediately, but it helps to notice that Danish vowels often carry a lot of meaning, so practicing ø, å, and endings like -en is important.