Definite Noun + си

1. Where it goes. Си follows the first word of the noun phrase, and that word takes the article:

• Взех чантата си. (I took my bag.)
• Продадохме старата си кола. (We sold our old car.)

Most singular family words drop the article, just as with майка ми: майка си, брат си, жена си (see kinship terms). Син and мъж keep it: сина си, мъжа си. In the plural they keep it: децата си, родителите си.

In everyday speech си often moves to the verb, and the noun keeps its article: Взех си чантата means the same as Взех чантата си.

2. The same word for every person.

• Забрави ли ключовете си? (Did you forget your keys?)
• Тя се обажда на майка си всеки ден. (She calls her mother every day.)
• Децата играят с кучето си. (The children are playing with their dog.)

3. Why it matters in the third person. Му, ѝ, им point to someone other than the subject. So Иван взе колата си is Ivan's own car, but Иван взе колата му is another man's car. With аз and ти the meaning is clear either way, but careful Bulgarian still prefers си. Compare the short forms in short possessive forms.

4. Only for an owner who is the subject. Си cannot describe the subject itself. My brother lives in London is Брат ми живее в Лондон, because брат is the subject and there is no other subject to point back to.

5. Related words. The long form is свой: нещата си = своите неща. Do not confuse possessive си with the си of reflexive verbs (Купих си кафе, I bought myself a coffee) or with си meaning you are.