English has no reflexive possessive, so this is one of the genuinely new things Swedish asks you to learn. sin / sitt / sina means "his / her / its / their own," and it refers back to the subject of its own clause. The whole point is to disambiguate a sentence English leaves murky: He loves his wife — his own, or another man's? Swedish forces the distinction. Han älskar *sin fru is his own wife; Han älskar **hans fru* is somebody else's. This page teaches the form and the core rule; the side-by-side decision practice lives on sin vs hans/hennes.
The form: it agrees with the thing owned
sin / sitt / sina inflects exactly like the possessive min / mitt / mina — it agrees with the noun it modifies (the thing possessed), in gender and number, and not with the owner:
| Form | Agrees with | Example |
|---|---|---|
| sin | singular en-word | sin bil (his/her own car) |
| sitt | singular ett-word | sitt hus (his/her own house) |
| sina | any plural | sina barn (his/her/their own children) |
Because it tracks the possessed noun, a single male subject can use sin, sitt, and sina in one breath depending on what he owns:
Han tar med sig sin plånbok, sitt pass och sina nycklar.
He brings his (own) wallet, his (own) passport and his (own) keys. plånbok (en) → sin, pass (ett) → sitt, nycklar (plural) → sina — all for the same owner.
The core rule: 3rd person + subject + same clause
You may use sin/sitt/sina only when all three conditions hold:
- the possessor is in the 3rd person (han, hon, den, det, man, de — never jag, du, vi, ni);
- the possessor is the subject of the clause;
- the possessed noun is in the same clause as that subject.
When the possessor is the subject, use sin/sitt/sina. When the possessor is anyone else — even another 3rd person mentioned elsewhere — use the ordinary hans / hennes / dess / deras. This is the minimal pair to memorise:
Han tog sin bok.
He took his (own) book. The book belongs to the subject 'han' → sin.
Han tog hans bil.
He took his car — but a DIFFERENT man's car. 'hans' points to someone other than the subject.
So sin turns the spotlight inward onto the subject, while hans/hennes/deras throws it outward to someone else. English cannot do this in one word — it would resort to "his own" vs. "the other man's" to clarify. With a plural subject the same logic holds, and sina covers the plural possessed noun:
De älskar sina barn över allt annat.
They love their (own) children above all else. plural subject 'de' + their own kids → sina.
Föräldrarna oroade sig för deras framtid.
The parents worried about their future — where 'their' is some OTHER group's (e.g. the grandchildren's). For the parents' own future you'd need 'sin'.
Lisa ringde sin mamma, och sedan ringde hon hennes syster.
Lisa called her (own) mum, and then she called her (the mum's, or another woman's) sister. sin = Lisa's; hennes = someone else's.
Note that the 1st and 2nd persons never use sin: "I took my book" is Jag tog min bok, never Jag tog sin bok. This is the same boundary as the reflexive object sig in The Reflexive Pronoun sig — both are strictly 3rd-person tools.
Jag åt min lunch och du åt din.
I ate my lunch and you ate yours. Lower persons use min/din, NEVER sin — 'sin' is 3rd person only.
The killer detail: sin can never be part of the subject
Here is the rule most resources leave out, and it is what catches advanced learners. Because sin refers back to the subject, it cannot itself be inside the subject — a thing cannot refer back to itself before the subject even exists. So a sentence may never start with sin/sitt/sina as the possessor of its subject:
❌ Sin bil är röd.
Incorrect — 'sin' can't sit inside the subject. There's nothing earlier for it to refer back to.
✅ Hans bil är röd.
His car is red. When the possessive is part of the subject, you must use hans/hennes/deras.
The practical test: if the possessed noun is the (or part of the) subject, use hans/hennes/deras; sin is reserved for possessed nouns in the object or complement position, where a subject has already been established for it to point back to.
Hennes syster bor i Lund.
Her sister lives in Lund. The sister is the subject, so 'sin' is impossible — use hennes.
Anna sa att hennes syster bor i Lund.
Anna said that her sister lives in Lund. The 'her' belongs to a subordinate clause whose subject is 'syster', not Anna — so it's hennes, not sin (a same-clause failure too).
That last example also illustrates condition 3: sin must share a clause with the subject it refers to. Here "her sister" sits in a subordinate clause (att...) whose own subject is syster; Anna is not the subject of that clause, so sin is impossible.
Common Mistakes
❌ Han älskar hans fru. (meaning his own wife)
Incorrect for 'his own wife' — 'hans' means another man's wife. English has no reflexive possessive, so learners use 'hans' for everything.
✅ Han älskar sin fru.
He loves his (own) wife.
❌ Hon sålde sitt cyklar.
Incorrect — 'sin/sitt/sina' agrees with the possessed noun. 'cyklar' is plural, so it must be 'sina', not 'sitt'.
✅ Hon sålde sina cyklar.
She sold her (own) bikes.
❌ Jag glömde sin telefon.
Incorrect — 'sin' is 3rd person only. With 'jag' you must use 'min'.
✅ Jag glömde min telefon.
I forgot my phone.
❌ Sin bil står på gatan.
Incorrect — 'sin' can never be part of the subject; there's no prior subject to refer back to. Use 'hans/hennes'.
✅ Hans bil står på gatan.
His car is parked on the street.
❌ De tog hand om deras hund. (meaning their own dog)
Incorrect for 'their own dog' — 'deras' points to another group. For the subject's own dog, use 'sin'.
✅ De tog hand om sin hund.
They took care of their (own) dog.
Key Takeaways
- sin / sitt / sina = "his/her/its/their own," referring back to the subject of the same clause. English has no equivalent, so it is genuinely new.
- It agrees with the possessed noun (sin = en-word, sitt = ett-word, sina = plural), like min/mitt/mina — never with the owner.
- Use it only when the possessor is 3rd person, is the subject, and shares the clause with the owned noun. Otherwise use hans / hennes / dess / deras.
- The minimal pair: Han tog *sin bok (his own) vs. Han tog **hans bil* (another man's).
- The detail to remember: sin can never be inside the subject (✗ Sin bil är röd → Hans bil är röd).
Now practice Swedish
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Start learning Swedish→Related Topics
- The Reflexive Pronoun sigA2 — When the object of a verb is the same person as the subject, Swedish 1st and 2nd persons just reuse the ordinary object pronoun (jag tvättar mig, du tvättar dig) — but the 3rd person has a dedicated reflexive word, sig, for he/she/it/they/one. Using honom or henne instead of sig flips the meaning to 'someone else', a mistake English's '-self' suffix makes very easy to fall into.
- sin/sitt/sina vs hans/hennes/derasB1 — The decision procedure for Swedish's reflexive possessive. Use sin/sitt/sina ('one's own') when the owner is the third-person SUBJECT of the SAME clause; use hans/hennes/deras for everyone and everything else. 'Han tvättar sin bil' means he washes his OWN car; 'Han tvättar hans bil' means he washes some other man's car — a distinction English can't make in a single word. The hard part is embedded clauses, where 'sin' points to the nearest subject.
- Possessive DeterminersA1 — The words for 'my/your/his...' before a noun: min/mitt/mina, din/ditt/dina, vår/vårt/våra and sin/sitt/sina AGREE with the possessed noun's gender and number, while hans, hennes, dess, er and deras are INVARIABLE. The rule English habits keep breaking: a noun after any possessive goes BARE (min bil, never *min bilen) — no definite suffix, no front article.
- Using hans/hennes Instead of sinB1 — English has no reflexive possessive, so 'his own' defaults to hans — and that single transfer error changes meaning in Swedish, not just style: Han tvättade hans bil unambiguously says he washed SOMEONE ELSE'S car. This page drills the reflexive sin/sitt/sina against hans/hennes/deras, including the subject-constraint trap (sin can never sit in the subject).