Originalet ligger i en blå mapp, men kopian är borta.

Those are the definite singular endings in Swedish, like the in English.

• ett original = an original / the original
• originalet = the original
• en kopia = a copy
• kopian = the copy

The ending depends on the noun’s gender:

• ett-words often take -et in the definite singular
• en-words often take -en or -n; with kopia, it becomes kopian

So:

• originalet = the original
• kopian = the copy

Unfortunately, Swedish noun gender usually has to be learned with each noun.

In this sentence:

• ett original
• en kopia
• en mapp

That is why you get:

• originalet
• kopian
• en blå mapp

A good habit is to learn nouns together with their article:

• ett original
• en kopia
• en mapp

Because mapp is an en-word, and the adjective in the indefinite singular form for an en-word usually has no extra ending.

So:

• en blå mapp = a blue folder

Compare:

• en blå mapp
• ett blått original = a blue original document (if that made sense in context)

With an ett-word, the adjective often gets -tt:

• ett blått hus = a blue house

So blå is correct here because mapp is an en-word.

In Swedish, ligga is often used for where something is physically located, especially an object that is resting somewhere.

So:

• Originalet ligger i en blå mapp literally means something like The original is lying in a blue folder
• Natural English translation: The original is in a blue folder

Swedish often prefers verbs like:

• ligga = lie
• stå = stand
• sitta = sit

depending on how something is positioned or conceived.

For papers, documents, books, clothes, and many objects, ligga is very common.

No. Very often it just means is located or is in a place.

Examples:

• Boken ligger på bordet = The book is on the table
• Nycklarna ligger i väskan = The keys are in the bag

In many cases, translating ligger as lies would sound too literal in English. English usually just says is.

Yes. i is the standard preposition for in.

So:

• i en blå mapp = in a blue folder

This is completely normal Swedish:

• i en låda = in a box
• i väskan = in the bag
• i huset = in the house

är borta is a very common Swedish expression meaning:

• is gone
• is missing
• has disappeared
• sometimes is away, depending on context

In this sentence, kopian är borta most naturally means:

• the copy is gone
• the copy is missing

So borta does not mean only physical distance like far away. It can also mean that something is no longer there.

Because men means but, and it normally does not trigger inversion.

So you get normal subject-verb order after it:

• ..., men kopian är borta

That is different from many adverbs or fronted elements, which can cause verb-second inversion.

Compare:

• Originalet ligger i en blå mapp, men kopian är borta.
• I dag är kopian borta.

In the second example, I dag comes first, so the verb är comes before the subject kopian.

But after men, normal order stays:

• men kopian är borta

Because Swedish usually puts the definite article at the end of the noun as a suffix.

So instead of saying the original with a separate word, Swedish says:

• originalet

And instead of the copy, Swedish says:

• kopian

This is one of the biggest differences from English.

However, with adjectives in definite noun phrases, Swedish often uses both:

• den blå mappen = the blue folder

So:

• no adjective: mappen = the folder
• with adjective: den blå mappen = the blue folder

Because the sentence means a blue folder, not the blue folder.

Swedish uses:

• en blå mapp = a blue folder
• den blå mappen = the blue folder

Since the folder is being introduced without specifying that it is a particular known one, the indefinite form is used.

Here are the main forms:

• originalet → ett original
• ligger → infinitive ligga
• i → preposition in
• en blå mapp → noun en mapp, adjective blå
• men → but
• kopian → en kopia
• är → infinitive vara
• borta → adjective/adverb-like word meaning gone / away

Learning the base form helps you recognize patterns:

• ett original → originalet
• en kopia → kopian
• ligga → ligger
• vara → är

Yes. It is a full clause:

• kopian = subject
• är = verb
• borta = predicate/complement

Likewise, the first part is also a full clause:

• Originalet ligger i en blå mapp

The whole sentence is made of two clauses joined by men:

• Originalet ligger i en blå mapp
• men kopian är borta

This is very common sentence structure in Swedish.