Hun sidder i sofaen hele tiden, mens vi ser filmen.

Danish often uses a position verb where English might simply use to be.

• sidde = to sit
• stå = to stand
• ligge = to lie
• være = to be

So Hun sidder i sofaen is more natural than Hun er i sofaen if you want to describe her physical position. It means she is sitting there, not just that she is located there.

Sidder is the present tense of sidde.

• infinitive: at sidde = to sit
• present: sidder = sits / is sitting

In Danish, the present tense often covers both simple present and progressive meaning:

• Hun sidder = she sits / she is sitting

In this sentence, the natural English meaning is she is sitting.

This is a very common question because English and Danish do not always use the same prepositions.

In Danish, you often say:

• i sofaen = literally in the sofa, but naturally on the sofa
• i stolen = in the chair

The idea is that furniture like a sofa or armchair is often treated as something you sit in, not on, even though English usually says on the sofa.

So:

• Hun sidder i sofaen = She is sitting on the sofa

The -en is the definite article attached to the end of the noun.

So:

• en sofa = a sofa
• sofaen = the sofa

and

• en film = a film / movie
• filmen = the film / movie

Unlike English, Danish often puts the at the end of the noun instead of using a separate word.

Because the sentence refers to a specific film that both speaker and listener understand.

• vi ser filmen = we are watching the movie
• vi ser en film = we are watching a movie

So filmen suggests a particular movie, not just any movie.

Hele tiden usually means all the time or the whole time.

In this sentence, the most natural meaning is:

• the whole time

So the idea is that she stays sitting on the sofa during the entire period in which we are watching the movie.

Depending on context, hele tiden can also mean constantly, so learners should be aware that it can have either meaning.

Mens means while.

It links two actions happening at the same time:

• Hun sidder i sofaen hele tiden = She is sitting on the sofa the whole time
• mens vi ser filmen = while we are watching the movie

So mens introduces a time relationship between the two parts of the sentence.

Because mens introduces a subordinate clause, and Danish word order changes in subordinate clauses.

In a main clause, Danish normally has verb-second word order:

• Vi ser filmen
• Nu ser vi filmen

But after a subordinating word like mens, the clause keeps the more basic order:

• mens vi ser filmen

So the subject vi comes before the verb ser.

This is an important pattern in Danish:

• main clause: often verb in second position
• subordinate clause: subject + verb

Because se can be used in two different ways.

• se noget = see/watch something
• se på noget = look at something

When you are talking about watching a movie, Danish normally says:

• se en film
• se filmen

So vi ser filmen means we are watching the movie.

If you said ser på filmen, it would sound more like looking at the movie/screen, not the normal way to say watching a movie.

Yes. Danish often uses the simple present where English uses am/is/are + -ing.

So:

• Hun sidder = she is sitting
• vi ser filmen = we are watching the movie

There is no separate progressive form like English is sitting or are watching. The present tense and the context do that job.

Yes, some parts can move, depending on what you want to emphasize.

For example, you could also say:

• Mens vi ser filmen, sidder hun i sofaen hele tiden.

This puts the while-clause first. Danish allows that kind of rearrangement.

But once a subordinate clause comes first, the main clause still follows normal Danish main-clause word order, so:

• Mens vi ser filmen, sidder hun ...

not

• Mens vi ser filmen, hun sidder ...

It is an adverbial phrase, and Danish has some flexibility with adverbials like this.

In this sentence:

• Hun sidder i sofaen hele tiden

the phrase hele tiden comes after i sofaen, which is very natural.

You may also hear other placements in different contexts, but the version here sounds normal and idiomatic. The exact placement can slightly affect emphasis, but not the basic meaning.