Hun sidder blandt venner.

Because Danish often uses position verbs where English would simply use to be.

The most common ones are:

• sidde = sit
• stå = stand
• ligge = lie

So Danish prefers to describe a person’s posture or position more specifically.
In Hun sidder blandt venner, sidder suggests that she is sitting / seated among friends, not just that she is there.

English often says She is among friends, but Danish more naturally uses sidder if the person is seated.

Yes. Sidder is the present tense of sidde.

A very important point for English speakers: Danish does not usually have a separate progressive form like is sitting. The plain present tense often covers both meanings:

• Hun sidder blandt venner = She sits among friends / She is sitting among friends

Which English translation sounds best depends on context.

The dictionary form is sidde = to sit.

Its present tense is sidder.
In Danish, the present tense is often made by adding -r to the infinitive:

• sidde → sidder
• bo → bor
• læse → læser

So here sidder is just the normal present-tense form.

Blandt means among or amid.

It is used when someone or something is within a group or surrounded by several others.

So in this sentence, blandt venner means the person is in the company of friends, inside that social group.

This is a very common question.

• blandt = among, amid, inside a group
• mellem = usually between, sometimes among in certain contexts

In many cases:

• blandt venner = among friends
• mellem to stole = between two chairs

A useful rule of thumb:

• Use blandt for a group or crowd
• Use mellem for more clearly separated things, positions, or choices

So Hun sidder blandt venner sounds natural because it describes being within a group of friends.

Because Danish, like English, often uses no article with an indefinite plural.

Compare:

• en ven = a friend
• venner = friends
• vennerne = the friends

So blandt venner literally means among friends, not among the friends.

That is completely normal Danish.

By itself, venner just means friends in a general or indefinite sense.

So Hun sidder blandt venner does not explicitly say that they are her friends, even though that may be implied by context.

If you wanted to be more specific, you could say:

• Hun sidder blandt sine venner = She is sitting among her friends

So the original sentence is a bit more general.

The word order is the normal Danish pattern for a main clause:

• Hun = subject
• sidder = finite verb
• blandt venner = prepositional phrase

So the structure is:

subject + verb + rest

That is the standard order in a simple statement.

Yes, you can.

Danish follows the verb-second rule in main clauses. That means the finite verb usually stays in the second position, even if something other than the subject comes first.

So both are possible:

• Hun sidder blandt venner
• Blandt venner sidder hun

The second version sounds more marked or literary, because it emphasizes blandt venner.

Usually it really does suggest a seated position.

So if you hear Hun sidder blandt venner, the natural picture is that she is physically seated among them.

That said, Danish uses posture verbs so naturally that they can sometimes feel less heavy than in English. Even then, sidder still normally points to the idea of sitting rather than just existing somewhere.

If she were standing among friends, Danish would more naturally say:

• Hun står blandt venner

The past tense of sidde is sad.

So:

• Hun sad blandt venner = She sat / was sitting among friends

Again, Danish does not normally need a separate progressive form, so sad can cover both sat and was sitting, depending on context.