The core distinction in one sentence: use sin/si/sitt/sine when the third-person possessor is the subject of the same clause (his/her/their own), and use hans/hennes/deres when the possessor is someone else. English "his car" is silent about whose car it is; Norwegian forces you to say — and choosing wrong doesn't just sound off, it changes who owns the thing.
This is the single most famous puzzle in Scandinavian grammar, and the good news is that it runs on one yes/no question. The bad news is that English gives you no instinct for it at all, so you have to build the reflex from scratch.
The one test that decides everything
Ask: does the thing belong to the subject of this clause?
- Yes → use the reflexive possessive sin/si/sitt/sine.
- No, it belongs to someone else → use hans (his), hennes (her), or deres (their).
Look at the minimal pair that linguists always reach for:
Ola elsker kona si.
Ola loves his (own) wife.
Ola elsker kona hans.
Ola loves his wife — i.e. some other man's wife.
In the first sentence, si points back to Ola, the subject: it's his own wife. In the second, hans points to a different man mentioned earlier — Ola is, somewhat scandalously, in love with another guy's wife. Same English translation, two completely different situations. That is the whole reason Norwegian keeps the distinction alive.
Han tok jakken sin og gikk.
He took his (own) jacket and left.
Han tok jakken hans ved en feil.
He took his jacket by mistake — someone else's jacket.
sin agrees with the thing owned, not the owner
Here is the trap that catches even careful learners. Sin is not chosen to match the owner's gender. It agrees with the possessed noun — exactly like an adjective. This is the opposite of English, where "his/her" tells you about the owner.
| Possessed noun | Form | Example |
|---|---|---|
| masculine (en-word) | sin | bilen sin (his/her car) |
| feminine (ei-word) | si | kona si (his/her wife) |
| neuter (et-word) | sitt | huset sitt (his/her house) |
| plural | sine | barna sine (his/her children) |
So whether the owner is a man or a woman, a house is always sitt and children are always sine:
Hun solgte huset sitt i fjor.
She sold her house last year.
Han savner barna sine.
He misses his children.
This is why "his/her" mapping breaks down: the same Norwegian word sitt covers his house, her house, and their house, because all three are neuter — the gender on the possessive is the house's gender, not the owner's.
sin can never be the subject (or inside the subject)
The reflexive must point back to the subject, so logically it can't be the subject — there would be nothing for it to point back to. A sentence can't refer back to itself before it has named who's acting.
❌ Sin bil er fin.
Incorrect — sin cannot start/be the subject.
✅ Bilen hans er fin.
His car is nice.
When the possessed thing is itself the subject, you have no choice: you must use hans/hennes/deres, because there is no separate subject for sin to attach to.
Hennes mor bor i Bergen.
Her mother lives in Bergen. (the mother is the subject)
Boka hans ligger på bordet.
His book is lying on the table.
The same applies to anything contained within the subject phrase. If the possessor is buried inside the subject, use hans/hennes, not sin:
Ola og kona hans kom for sent.
Ola and his wife arrived late. (kona hans is part of the subject)
Only third person uses sin
The reflexive possessive exists only in the third person (han, hun, de, and any noun like Ola, læreren, barna). For I, you, and we, the possessive is automatically "own" anyway — min, din, vår already point back to the subject, so no special form is needed.
Jeg tok bilen min.
I took my car. (always min, never a reflexive form)
Du glemte boka di.
You forgot your book.
So the sin/hans choice only ever arises when the owner is he, she, they, or a named third party. With jeg/du/vi/dere, just use the ordinary possessive and move on.
Edge cases and gray areas
The subject can be a noun, not just a pronoun. "Subject" means the grammatical subject, whoever it is. Læreren glemte nøklene sine — the teacher forgot his/her (own) keys. Læreren is the subject, so sine points back to it.
Katten slikket potene sine.
The cat licked its (own) paws.
Plural owners use deres for "someone else's." When they own something that belongs to another group, it's deres; when it's their own, it's sin/si/sitt/sine.
De inviterte vennene sine.
They invited their (own) friends.
De inviterte vennene deres.
They invited their friends — some other people's friends.
Inside a subordinate clause, the relevant subject is that clause's subject. The reflexive looks to the subject of its own clause, not the main clause: Han sa at Kari hadde solgt bilen sin most naturally means Kari sold Kari's car (the subject of "had sold").
deres is also "your" (plural). Don't confuse the possessor sense: deres can mean their (3rd person, someone else's) or your (addressing several people). Context decides — but the sin/hans contrast only concerns the 3rd-person their.
Common Mistakes
These errors nearly all come from English having a single ambiguous "his/her" with no own-vs-other distinction.
❌ Han elsker kona hans.
Incorrect (if you mean his own wife) — hans means another man's wife.
✅ Han elsker kona si.
He loves his (own) wife.
❌ Hun tok jakken hennes.
Incorrect (if it's her own) — hennes points to another woman.
✅ Hun tok jakken si.
She took her (own) jacket.
❌ Sin bil er rød.
Incorrect — sin can never be (in) the subject.
✅ Bilen hans er rød.
His car is red.
❌ Hun solgte huset sin.
Incorrect agreement — hus is neuter.
✅ Hun solgte huset sitt.
She sold her house.
❌ Jeg tok bilen sin.
Incorrect — sin is third person only; with jeg use min.
✅ Jeg tok bilen min.
I took my car.
Decision summary
| Question | Answer | Use |
|---|---|---|
| Is the owner 1st/2nd person (jeg, du, vi, dere)? | Yes | min, din, vår (no reflexive) |
| 3rd-person owner — is it the same as this clause's subject? | Yes (own) | sin / si / sitt / sine (agrees with the thing) |
| 3rd-person owner — does it belong to someone else? | No (other) | hans / hennes / deres |
| Is the possessed thing itself the subject? | — | hans / hennes / deres (sin can't be subject) |
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Start learning Norwegian→Related Topics
- sin vs hans/hennes: The Reflexive PossessiveB1 — The classic Scandinavian trap: sin/si/sitt/sine refers possession back to the SUBJECT of the clause (han tok jakken sin = his own jacket), while hans/hennes/deres points to someone else (jakken hans = another man's). sin agrees with the possessed noun's gender and number, never the owner, and can never be part of the subject — two rules English has no analogue for.
- Possessive Pronouns: min, din, hans, vårA2 — The full possessive paradigm — agreeing min/mitt/mine and frozen hans/hennes/deres — plus standalone use ('den er min') and the famous sin-vs-hans puzzle, where Norwegian distinguishes 'his own' from 'his (someone else's)' with a dedicated word English simply lacks.
- Possessive Determiners and Their PositionA2 — Norwegian possessives like min/mitt/mine agree with the possessed noun and sit most naturally AFTER it — 'bilen min', 'boka mi', 'huset mitt' — with the definite noun, the opposite of the English order learners reach for.
- når vs da: Two Words for 'When'B1 — English 'when' splits into two Norwegian words: da for a single past event, når for the present, the future, and repeated past — with a clean test for choosing.