Learn Hardcore Swedish: Hennes bok ligger i huset, och hans bok ligger i biblioteket. - Her book is in the house, and his book is in the library.

ligger (lie) for things lying/resting on a surface or just “situated” somewhere
står (stand) for things upright (bottles, buildings, TVs)
sitter (sit) for things attached/affixed (a button sits on a shirt)

So Boken ligger i huset sounds more natural than Boken är i huset. You would use är more freely with people/animals: Han är i huset. If you’re unsure, default to ligger for small objects.

Why is it hennes bok, not hennes boken?

With possessive determiners (min, din, hans, hennes, vår, er, deras) the noun stays morphologically indefinite:

Correct: hennes bok, hans bok
Incorrect: hennes boken, hans boken

If you add an adjective, the adjective takes the definite form, but the noun still has no definite ending:

hennes nya bok, hans gamla bok

What’s the difference between hennes and sin/sitt/sina?

hennes refers to a female possessor who is someone else (not the subject of the same clause).
sin/sitt/sina is reflexive and refers back to the subject of the same clause.

Examples:

Hon lämnade sin bok i huset. = She left her own book.
Hon lämnade hennes bok i huset. = She left another woman’s book.

Does hans ever get capitalized? How do I tell it apart from the male name Hans?

The possessive pronoun hans is normally lowercase. It’s only capitalized at the start of a sentence because of sentence case: Hans bok ligger … Context tells you whether it’s the pronoun (his) or the name Hans. In the middle of a sentence after a comma, it should be lowercase when it’s the pronoun: …, och hans bok ….

Why are huset and biblioteket in the definite form?

They refer to specific places (“the house,” “the library”). Both nouns are neuter, so their definite singular ends in -et:

ett hus → huset
ett bibliotek → biblioteket

Indefinite alternatives would be i ett hus (in a house) and i ett bibliotek (in a library).

Could I say på biblioteket instead of i biblioteket?

Yes, with a nuance:

i biblioteket = inside the building (physical interior)
på biblioteket = at the library as a place of activity (more idiomatic for “at the library”)

For houses, you typically use i huset. Swedish often uses på with many public places: på jobbet, på universitetet, på bio.

If the book is “her/his book,” why isn’t bok definite?

In Swedish, possessives make the noun definite in meaning, but you don’t use the definite suffix on the noun. So it’s hennes bok, not a double-definite form. With demonstratives you do use double definiteness: den röda boken, but with possessives it’s hennes röda bok.

What are the key forms of bok, hus, and bibliotek?

bok (common gender):
- singular: en bok, boken
- plural: böcker, böckerna
hus (neuter):
- singular: ett hus, huset
- plural: hus, husen
bibliotek (neuter):
- singular: ett bibliotek, biblioteket
- plural: bibliotek, biblioteken

Is the comma before och required?

No. In modern Swedish you usually do not put a comma before och when joining two main clauses. Many would write: Hennes bok ligger i huset och hans bok ligger i biblioteket. The comma isn’t catastrophic, but it’s normally omitted.

Can I change the word order to I huset ligger hennes bok, och i biblioteket ligger hans bok?

Yes. Swedish main clauses are verb-second (V2). If you front an adverbial like I huset, the finite verb (ligger) must come next: I huset ligger hennes bok. Your alternative is correct (and stylistically fine to emphasize locations).

Can I use finns instead of ligger?

Often, yes, with a slight shift:

Boken ligger i biblioteket. = It’s lying/located there (posture/location).
Boken finns i biblioteket. = It exists/can be found there (availability/existence). Both are natural; choose based on the nuance you want.

Why is the verb ligger the same in both clauses? Don’t verbs change with person/number?

Swedish verbs don’t conjugate for person or number. Present tense is the same for all subjects: jag/du/han/hon/vi/ni/de ligger.

Does hennes change with the noun’s gender or number?

No. hennes (and hans) are invariable:

hennes bok, hennes böcker, hennes hus
hans bok, hans böcker, hans hus

Could I replace hennes/hans with sin/sitt/sina in this sentence?

Not here. The subject of each clause is the book itself (hennes bok, hans bok), so there’s no higher subject within the same clause for sin/sitt/sina to refer back to. You’d use the reflexive if the possessor is the subject: Hon har sin bok i huset. / Han har sin bok i biblioteket.

Is there a more idiomatic way to say “at home” instead of i huset?

Yes, hemma means “at home.” For example: Hennes bok ligger hemma. Use i huset when you want to emphasize inside a specific house/building.