Jeg sidder i tandlægestolen.

Because Danish very often uses a position verb where English would simply use be.

Here, sidder means is sitting / sits, from at sidde. Since a person in a dentist’s chair is in a seated position, Jeg sidder i tandlægestolen is the natural way to say it.

Compare:

• Jeg sidder i tandlægestolen. = I am sitting in the dentist’s chair.
• Jeg er i tandlægestolen. = I am in the dentist’s chair.

The second one is possible, but it focuses more on location and sounds less specific about posture. Danish often prefers sidde, stå, or ligge when posture matters.

Sidder is the present tense of at sidde.

So:

• at sidde = to sit
• sidder = sit / am sitting / is sitting

Danish does not usually have a separate form like the English am sitting. The simple present often covers that meaning.

So Jeg sidder i tandlægestolen can naturally mean:

• I sit in the dentist’s chair
• I am sitting in the dentist’s chair

The context tells you which English version is best.

This is a very natural question, because English speakers often expect on with chairs.

In Danish, both i and på can be used with seating in different situations, but i is especially natural when the seat feels more like something you sit in, not just on. A dentist’s chair is large, shaped, and enclosing, so i tandlægestolen sounds very idiomatic.

It is similar to English, where people often say in the dentist’s chair rather than on the dentist’s chair.

A useful rough idea:

• på = on a surface
• i = in something, inside it, or in a more enclosed/contained position

For an ordinary chair, på en stol is very common. But with tandlægestolen, i sounds very natural.

Because Danish, like English, makes compound nouns—but Danish usually writes them as one word.

So:

• tandlæge = dentist
• stol = chair
• tandlægestol = dentist’s chair

Then the definite ending is added:

• tandlægestolen = the dentist’s chair

This is very common in Danish. The last part is the main noun, and the earlier part describes it.

More examples:

• kaffekop = coffee cup
• skolelærer = school teacher
• bilnøgle = car key

The -en is the definite article: it means the.

So:

• en stol = a chair
• stolen = the chair

And with the compound:

• en tandlægestol = a dentist’s chair
• tandlægestolen = the dentist’s chair

This is one of the big differences from English: Danish usually puts the at the end of the noun instead of using a separate word before it.

Because in Danish, the definite article is usually attached to the noun itself.

So instead of saying something like the dentist’s chair, Danish often says the equivalent of dentist-chair-the:

• tandlægestolen

That is the normal pattern.

You only get a separate definite word in certain other structures, especially when there is an adjective:

• tandlægestolen = the dentist’s chair
• den store tandlægestol = the big dentist’s chair

So without an adjective, the ending alone is enough.

Stol is an en-word (common gender).

That is why you get:

• en stol
• stolen

If it were an et-word, the definite ending would usually be -et instead.

This matters because Danish nouns must be learned with their gender:

• en tandlægestol
• tandlægestolen

The basic order is:

subject + verb + other information

So here:

• Jeg = subject
• sidder = verb
• i tandlægestolen = prepositional phrase showing location

So:

Jeg sidder i tandlægestolen.

This is a normal, neutral Danish main clause.

Also, Danish is a V2 language, which means the finite verb usually stays in the second position in main clauses. For example, if you move the location to the front, the verb still comes second:

• I tandlægestolen sidder jeg.

That version is more marked or emphatic, but it shows the pattern.

For a negative sentence, Danish usually puts ikke after the finite verb in a main clause:

• Jeg sidder ikke i tandlægestolen.
• I am not sitting in the dentist’s chair.

For a yes/no question, Danish usually puts the verb first:

• Sidder du i tandlægestolen?
• Are you sitting in the dentist’s chair?

So the patterns are:

• Statement: Jeg sidder ...
• Negative: Jeg sidder ikke ...
• Question: Sidder du ... ?

An approximate pronunciation for learners is:

TAN-leh-yuh-stoh-len

A few helpful points:

• tand: the d is often very light in connected speech
• læge: the æ is a front vowel, somewhat like the vowel in bed or cat, depending on your accent
• the g in læge is soft, often sounding a bit like y
• stolen has stress on sto-

So tandlæge does not sound like it is pronounced exactly the way it is spelled in English-style reading.

If you want a learner-friendly rough breakdown:

• tandlæge ≈ TAN-leh-yuh
• stolen ≈ STOH-len

Yes.

Tandlæge is made from:

• tand = tooth
• læge = doctor

So literally it is something like tooth-doctor, which is the normal Danish word for dentist.

Then Danish builds another compound on top of that:

• tandlæge
  • stol = tandlægestol

So tandlægestolen is a compound inside a compound, which is very normal in Danish.