Min søster vil slette den gamle fil, men først laver hun en kopi.

Because søster is a common-gender noun in Danish, and common-gender nouns take en in the indefinite form and use possessives like min.

• en søster = a sister
• min søster = my sister

If the noun were neuter gender, you would use mit instead:

• et hus = a house
• mit hus = my house

So the form of my depends on the gender of the noun.

Here, vil means wants to or intends to.

It is the present tense of ville. In a sentence like this, it often expresses intention:

• Hun vil slette filen = She wants to delete the file / She is going to delete the file

So Min søster vil slette... means that your sister intends or wants to do that action.

Because slette is the infinitive form, and it comes after the modal verb vil.

In Danish, modal verbs such as vil, kan, skal, må, bør are followed by the infinitive without at:

• hun vil slette
• jeg kan komme
• vi skal gå

So:

• vil = finite verb
• slette = infinitive

You would use sletter if it were the main present-tense verb by itself:

• Hun sletter filen = She deletes/is deleting the file

Because after a modal verb, Danish normally uses the infinitive without at.

So you say:

• hun vil slette
• jeg kan læse
• de skal arbejde

Not:

• hun vil at slette ❌

This is similar to English, where we also say she wants to delete, but with Danish modal verbs like vil, kan, and skal, there is no equivalent of to before the infinitive.

This is the definite form: the old file.

It has three parts:

• den = the for a common-gender noun
• gamle = old in the definite/adjective form
• fil = file

A very common Danish pattern is:

• den/det/de + adjective + noun

So:

• den gamle fil = the old file
• det gamle hus = the old house
• de gamle bøger = the old books

Notice that the adjective becomes -e here: gammel → gamle.

There are two important rules here.

1. The adjective comes before the noun.
So Danish says:

• den gamle fil

not:

• filen gamle ❌

2. In this structure, the adjective takes the definite form -e.
So it must be:

• den gamle fil

not:

• den gammel fil ❌

This is one of the standard adjective patterns in Danish:

• en gammel fil = an old file
• den gamle fil = the old file

Men means but, and først means first.

Together, men først means something like:

• but first
• but before that

So the sentence contrasts two actions:

1. she wants to delete the old file
2. but before doing that, she makes a copy

It signals sequence: the copy happens before the deletion.

Because Danish follows the V2 rule in main clauses: the finite verb usually comes in the second position.

In the second clause, først is placed first for emphasis, so the verb must come next:

• først laver hun en kopi

Structure:

• først = first element
• laver = finite verb in second position
• hun = subject

This is very common in Danish:

• I dag arbejder jeg hjemme.
• Nu går vi.
• Først laver hun en kopi.

English learners often expect først hun laver, but Danish main clauses do not work that way.

Here, laver means makes.

• lave en kopi = make a copy

This is a normal Danish expression. In English, we often say make a copy, so this matches quite well.

You may also hear related expressions in other contexts, but lave en kopi is very natural and common.

Because kopi is a common-gender noun, so its indefinite article is en.

• en kopi = a copy
• kopien = the copy

If it were a neuter noun, it would take et, but kopi is not neuter.

The nouns in this sentence are all common gender:

• en søster
• en fil
• en kopi

That is why you see forms like:

• min søster
• den gamle fil
• en kopi

This is useful because gender affects articles, possessives, and adjective patterns.

Yes, but the word order changes depending on where you put it and what you want to emphasize.

The sentence you have is:

• ...men først laver hun en kopi.

This strongly highlights first.

You could also say:

• ...men hun laver først en kopi.

That is also natural, but it places the subject first and sounds a little less fronted or dramatic.

Both are possible, but:

• først laver hun... = stronger emphasis on sequence
• hun laver først... = more neutral

In both cases, the meaning is basically the same.

Yes. En fil is the normal Danish word for a file, including a computer file.

So:

• slette en fil = delete a file
• gemme en fil = save a file
• åbne en fil = open a file

Just be aware that fil can also mean other kinds of file in other contexts, but in modern everyday Danish it is very commonly used for computer files.

Then en kopi would become kopien or possibly den kopi, depending on structure, but most naturally here it would be:

• ...men først laver hun kopien.

However, in real Danish, if you mean she is making a copy in general, en kopi is much more natural.

• en kopi = a copy, any copy
• kopien = the copy, a specific one already known from context

So the original sentence uses en kopi because it introduces a new thing, not a previously mentioned specific copy.