Hun virker stadig interesseret.

Virker means something like seems, appears, or comes across as. So Hun virker stadig interesseret is softer and less direct than saying Hun er stadig interesseret.

• Hun er stadig interesseret = she is still interested
• Hun virker stadig interesseret = she seems/appears to still be interested

Danish often uses virke when the speaker is judging from behavior, expression, or general impression, rather than stating something as a fact.

Virker is the present tense of at virke.

The infinitive is:

• at virke = to seem / to function / to have an effect, depending on context

Some common forms are:

• virker = present tense
• virkede = past tense
• har virket = has seemed / has functioned

In this sentence, it means seems.

Stadig is an adverb meaning still, and in this sentence it modifies the whole idea of her seeming interested. Danish adverbs often appear before the adjective or participle they are closely connected to.

So:

• Hun virker stadig interesseret = She still seems interested

This word order is very natural in Danish. Compare:

• Hun er stadig træt = She is still tired
• Han virker stadig sur = He still seems angry

Not in normal standard Danish. That sounds unnatural.

The natural position is:

• Hun virker stadig interesseret

Danish word order is less flexible than English in cases like this. Stadig normally comes before the adjective here, not after it.

Here, interesseret is used as an adjective describing hun.

For en-words and for common singular usage with a person, the basic form is:

• interesseret

Examples:

• en interesseret mand
• en interesseret kvinde
• Hun er interesseret

The form interesserede is used mainly in:

• plural: De er interesserede
• definite forms: den interesserede elev

So because hun is singular, interesseret is correct.

Historically, it comes from a participle-like form, but in sentences like this it functions as an adjective.

So in practice, for a learner, it is best to think of it as an adjective meaning interested:

• Hun er interesseret
• Hun virker interesseret

This is similar to English, where interested also looks like a past participle but often behaves like an adjective.

Yes. At virke is a very common Danish verb with several meanings. The most common ones are:

• to seem / appear
  • Hun virker glad = She seems happy
• to function / work
  • Computeren virker ikke = The computer does not work
• to have an effect
  • Medicinen virker = The medicine is working

In your sentence, the meaning is clearly seem/appear because it is followed by an adjective: interesseret.

Because Danish can use virke directly with an adjective.

So:

• Hun virker interesseret

literally corresponds to:

• She seems interested

English also works this way with seem. You do not need to be:

• She seems interested not
• She seems to be interested unless you want a slightly different style or emphasis

Danish can also say:

• Hun virker til at være interesseret

But that is longer and less direct. Hun virker interesseret is more natural here.

Hun is the third-person singular feminine subject pronoun, meaning she.

It is the subject form, so it is used because she is the one doing the seeming:

• Hun virker ...

Compare:

• hun = she
• hende = her

Examples:

• Hun virker træt = She seems tired
• Jeg ser hende = I see her

You would usually change virker to virkede:

• Hun virkede stadig interesseret = She still seemed interested

Everything else can stay the same.

You could also form perfect tenses, depending on context:

• Hun har stadig virket interesseret = She has still seemed interested

But the most straightforward past version is:

• Hun virkede stadig interesseret

It is neutral, standard Danish. It works well in everyday speech and in writing.

It is neither especially formal nor especially casual. That makes it a very useful sentence pattern to learn:

• Hun virker rolig = She seems calm
• Han virker nervøs = He seems nervous
• De virker glade = They seem happy

A rough learner-friendly guide is:

• interesseret ≈ in-te-re-SE-ret

But natural Danish pronunciation is more reduced and smoother than that spelling suggests.

A few things to keep in mind:

• The r sounds are Danish, not English r
• Unstressed syllables are often weakened
• The ending -et is not pronounced like a strong English et

If you are learning pronunciation, it is best to hear native audio and repeat whole chunks such as:

• virker stadig interesseret

rather than trying to build it sound by sound from the spelling.