Sin, sitt, sina: the difference between sin and hans or hennes
The Swedish reflexive possessive explained. Why Erik kysser sin fru and Erik kysser hans fru describe two very different evenings, with a rule you can trust.
Swedish has two ways to say "his", and they are not interchangeable. Erik kysser sin fru means Erik kisses his own wife. Erik kysser hans fru means Erik kisses some other man's wife. One letter of difference in the possessive, a completely different evening for everyone involved. This is the distinction Swedish is famous for among learners, and the rule behind it is genuinely learnable.
The rule
Inside a clause, when "his", "her" or "their" points back at the subject of that clause, Swedish uses sin/sitt/sina. When it points at anyone else, Swedish uses hans, hennes or deras.
- Anna träffar sin syster. Anna meets her own sister.
- Anna träffar hennes syster. Anna meets her sister, and "her" is some other woman mentioned earlier.
English "his/her" covers both cases and lets context sort it out, which is why English tolerates sentences like "Erik met his brother and his wife" without knowing whose wife came along. Swedish simply refuses to be ambiguous here. Once you can use sin correctly, you'll start missing it in English.
The forms
Sin agrees with the thing owned, not with the owner, following the usual en/ett/plural pattern:
- Hon älskar sin man. She loves her husband. (en word)
- Hon säljer sitt hus. She is selling her house. (ett word)
- Hon läser för sina barn. She reads to her children. (plural)
It exists only in the third person. Min, din, vår and er work the same whether or not they point at the subject, so first and second person never have this problem. The generic man does take it: Man älskar sina barn. One loves one's children.
Where sin can never appear: in the subject
Sin points back at a subject, so it cannot be part of the subject itself. There is nothing for it to point to yet.
- Hans fru är läkare. His wife is a doctor. Correct, and the only option.
- "Sin fru är läkare" is impossible Swedish, always.
If the possessive comes before the verb, in subject position, it must be hans/hennes/deras. No exceptions.
The subtlety that earns this topic its reputation
Each clause runs the rule with its own subject. In a subordinate clause, sin can only point at that clause's subject, not at the main sentence's:
- Erik säger att hans fru är trött. Erik says that his wife is tired.
That's Erik's own wife, and it is still hans, because inside the att clause the subject is "his wife" herself; sin would have nothing legitimate to attach to. Learners who have just mastered "own = sin" find this genuinely surprising, and even advanced Swedish speakers argue about edge cases at dinner tables. If you get the plain main-clause rule right, you're ahead of the curve; let the clause-boundary refinement settle in over time.
A test you can run in your head
When you're unsure, ask: who is the subject of this verb, and does the owned thing belong to them? Yes → sin/sitt/sina. No, or the possessive sits in the subject → hans/hennes/deras. That test resolves nearly every sentence you'll produce at this level.
Hear the difference
Five sentences, including one where hennes is the right choice.
Swedish
Erik älskar sin fru.
Anna läser för sina barn.
Han tvättar sin bil varje lördag.
Maria är sjuk, så Anna lånar hennes cykel.
De säljer sitt hus i Falun.
English
Erik loves his wife.
Anna reads to her children.
He washes his car every Saturday.
Maria is sick, so Anna is borrowing her bike. (Maria's bike, which is exactly why it's hennes.)
They are selling their house in Falun.