Learn Hardcore Danish: Hun glemmer sit pas på bordet i stuen. - She forgets her passport on the table in the living room.

Current action / general truth:
- Hun glemmer sit pas på bordet i stuen.
  = She (typically / often) forgets her passport on the table in the living room.
Near future (especially with a time expression):
- I morgen glemmer hun sikkert sit pas på bordet i stuen.
  = Tomorrow she will probably forget her passport on the table in the living room.

If you want to talk about a completed past action, you would use:

Hun glemte sit pas på bordet i stuen.
= She forgot / left her passport on the table in the living room.

So the bare present glemmer can be understood as present, habitual, or (with context) future, similar to English forgets / is going to forget.

Why is it sit pas and not hendes pas for her passport?

Danish has special reflexive possessive pronouns: sin, sit, sine.
They are used when the possessor is the subject of the same clause.

Hun glemmer sit pas …
= She forgets her own passport.

If you said:

Hun glemmer hendes pas …

this would normally be understood as:

She forgets her (another woman’s) passport.

So:

sin / sit / sine → “her/his/their own” (refers back to the subject)
hendes / hans / deres → “her/his/their” (someone else, not the subject)

In this sentence, the subject hun is the owner of the passport, so sit is correct.

How do I know when to use sin, sit, or sine?

They all mean roughly his/her/their own, but they agree with the noun they describe:

sin – with common gender singular nouns (en-words)
- Hun glemmer sin taske.
  = She forgets her (own) bag. (taske is an en-word: en taske)
sit – with neuter gender singular nouns (et-words)
- Hun glemmer sit pas.
  = She forgets her (own) passport. (pas is an et-word: et pas)
sine – with plural nouns of either gender
- Hun glemmer sine pas.
  = She forgets her (own) passports.

So you must know the gender and number of the noun to choose correctly.

What gender are pas, bord, and stue, and how does that affect the forms in the sentence?

pas – neuter (et pas)
- Therefore: sit pas (not sin pas)
bord – neuter (et bord)
- Definite form: bordet = the table
stue – common gender (en stue)
- Definite form: stuen = the living room

The genders matter for:

The possessive sin / sit / sine → you need sit pas because pas is neuter.
The definite suffix:
- et bord → bordet
- en stue → stuen

Why is it på bordet and not i bordet?

Danish uses different prepositions depending on the spatial relationship, similar to English:

på = on (a surface)
- på bordet = on the table
- på gulvet = on the floor
- på væggen = on the wall
i = in / inside
- i skuffen = in the drawer
- i tasken = in the bag
- i rummet = in the room

A passport lying on the flat surface of the table is naturally described with på:

Hun glemmer sit pas på bordet …
= She leaves/forgets her passport on the table.

I bordet would mean “inside the table” (which normally makes no sense).

Why do bordet and stuen have endings instead of a separate word for the?

Danish usually marks definiteness with a suffix instead of a separate article:

et bord = a table → bordet = the table
en stue = a living room → stuen = the living room

So in the sentence:

på bordet = on the table
i stuen = in the living room

You can see den / det before a noun, but then the noun also takes the definite suffix:

det bord = that table (demonstrative)
det bordet = that/this particular table (more emphatic, often spoken)

For a simple the, the normal form is just bordet, stuen.

Can I change the order of på bordet i stuen? For example, say i stuen på bordet?

Yes, both are grammatically possible:

Hun glemmer sit pas på bordet i stuen.
Hun glemmer sit pas i stuen på bordet.

In practice:

på bordet i stuen is more natural: it goes from smaller location (table) to larger (living room) as one unit.
i stuen på bordet is also understandable, and some speakers might use it, but på bordet i stuen is more typical.

What you cannot do is split them unnaturally, like:

✗ Hun glemmer på bordet sit pas i stuen.

Adverbials of place usually come after the object, and the phrase på bordet i stuen functions as one longer place description.

Could I also say Hun har glemt sit pas på bordet i stuen? What is the difference from Hun glemmer …?

Yes, you can say both, but there is a difference in aspect/time focus:

Hun glemmer sit pas på bordet i stuen.
Present tense.
- Can describe a habitual situation (she often does this), or
- A present-time narrative (like telling a story in the present).
Hun har glemt sit pas på bordet i stuen.
Present perfect.
- Focuses on a completed past action with relevance now:
  She has (already) forgotten/left her passport on the table.

In everyday speech, har glemt is what you normally use when you discover the problem:

Åh nej, jeg har glemt mit pas!
= Oh no, I’ve forgotten my passport!

Does glemmer always mean physically leaving something behind, or can it also be mental forgetting?

At glemme covers both meanings, just like English to forget:

Physical / practical forgetting (leaving something)
- Hun glemmer sit pas på bordet.
  = She leaves/forgets her passport on the table.
Mental forgetting (not remembering)
- Hun glemmer hans navn.
  = She forgets his name.
- Jeg glemmer altid, hvad hun hedder.
  = I always forget what she’s called.

Context tells you whether it is about not remembering in your head or leaving something somewhere.

Why is it i stuen and not just stuen or i stue?

You need i because Danish, like English, normally uses a preposition before a place noun in this kind of construction:

i stuen = in the living room
på kontoret = at the office
i køkkenet = in the kitchen

You also need the definite form because it refers to a specific room:

stue = (a) living room
stuen = the living room

So:

Hun glemmer sit pas i stuen.
= She forgets her passport in the living room.

Without i:

✗ Hun glemmer sit pas stuen.
is incorrect.

And i stue (indefinite) is odd in normal usage; you usually mean a specific room, so you say i stuen.

Is at glemme a reflexive verb in Danish? Do I need sig somewhere?

In this sentence, at glemme is not reflexive:

Hun glemmer sit pas …
Verb glemmer
- direct object sit pas.

There is a reflexive expression at glemme sig, but it has a different meaning:

Hun glemmer sig, når hun arbejder.
= She loses track of time / forgets herself when she works.

Here:

glemmer sig = forgets herself (gets carried away)
In Hun glemmer sit pas …, sit pas is just a normal object, and sit is a reflexive possessive pronoun, not a reflexive object pronoun.