Definite and indefinite possessive pronouns
The Bulgarian possessive pronouns have two forms: indefinite – roughly corresponding to the English possessive pronouns (This book is mine), and definite – roughly corresponding to the English possessive adjectives (This is my book).
The indefinite forms indicate that we are talking about an object or a person as a representative of a whole group of similar objects, and the definite forms indicate that we are talking about a particular object or person.
Gender forms of the singular possessive pronouns
Both the indefinite and the definite singular possessive pronouns in Bulgarian have different forms for the various the genders of the possession:

Plural forms of the possessive pronouns
The plural forms do not make gender distinctions:

Examples:
Indefinite singular
Този компютър е мой/твой/негов/неин/негов/наш/ваш/техен. = This is a computer of mine/yours/his/hers/its/ours/yours/theirs. (indefinite masculine possession: I have many computers and this is one of them.)
Тази книга е моя/твоя/негова/нейна/негова/наша/ваша/тяхна. = This is a book of mine/yours/his/hers/its/ours/yours/theirs. (indefinite feminine possession: I have many books and this is one of them.)
Това куче е моe/твоe/неговo/нейно/негово/наше/ваше/тяхно. = This is a dog of mine/yours/his/hers/its/ours/yours/theirs. (indefinite neutral possession: I have many dogs and this is one of them.)
Definite singular
Това е моят/твоят/неговият/нейният/неговият/нашият/вашият/техният компютър. = This is my/your/his/her/its/our/your/their computer. (definite masculine possession: I either have only one computer or you know which particular computer of mine I am talking about.)
Това е моятa/твоятa/неговaтa/нейнaтa/неговaтa/нашaтa/вашaтa/тяхната книга. = This is my/your/his/her/its/our/your/their book. (definite feminine possession: I either have only one book or you know which particular book of mine I am talking about.)
Това е моето/твоето/неговото/нейното/неговото/нашето/вашето/тяхното куче. = This is my/your/his/her/its/our/your/their dog. (definite neutral possession: I either have only one dog or you know which particular dog of mine I am talking about.)
Indefinite plural
Тeзи компютри/книги/кучета са мои/твои/негови/нейни/негови/наши/ваши/техни. = Thеsе are some computers/books/dogs of mine/yours/his/hers/its/ours/yours/theirs. (indefinite possession, plural: I have many computers/books/dogs and these are some of them.)
Definite plural
Това са моите/твоите/неговите/нейните/неговите/нашите/вашите/техните компютри/книги/кучета. = These are my/your/his/her/its/our/your/their computers/books/dogs. (definite possession, plural: I either have only these computers/books/dogs or you know which particular group of computers/books/dogs I am talking about.)
Other examples:
Това куче мое ли е ? – Is this one of my dogs/Is this dog mine?
Това куче моето ли е? – Is this my dog?
Това куче твое ли е? – Is this one of your dogs/Is this dog yours?
Това куче твоето ли е? – Is this your dog?
Този компютър негов ли е? – Is this one of his computers/Is this computer his?
Това неговият компютър ли е? – Is this his computer?
Тази книга нейна ли е? – Is this one of her books/Is this book hers?
Това нейната книга ли е? – Is this her book?
Тази чаша негова ли е? – Is this one of its cups/Is this cup its?
Това неговата чаша ли е? – Is this its cup?
Тази кола наша ли е? – Is this one of our cars/Is this car ours?
Това нашата кола ли е? – Is this our car?
Тази къща ваша ли е? – Is this one of your houses/Is this house yours?
Това вашата къща ли е? – Is this your house?
Този апартамент техен ли е? – Is this one of their flats/Is this flat theirs?
Това техният апартамент ли е? – Is this their flat?
Нашата кола е в гаража. – Our car is in the garage.
Нейният син е инженер. – Her son is an engineer.
Неговата дъщеря е учителка. – His daughter is a teacher.
Моите синове са близнаци. – My sons are twins.
Short forms of the possessive pronouns

Notice the change in word order and the word bearing the definite article when we use the long and when we use the short forms of the possessive pronouns:
моят компютър = компютърът ми
моята книга = книгата ми
моето куче = кучето ми
Reflexive possessive pronouns
There is a type of reflexive pronouns that signifies possession and is similar is usage to the possessive pronouns, but is more universal, meaning that it only changes according to the gender and number of the possession. It only has one short form that is used for all genders and numbers.

The definite forms of the possessive reflexive pronouns are more widely used than the indefinite forms.
Examples:

In the third person singular though, the “regular” possessive pronouns have a different meaning compared to the reflexive possessive pronouns:
Той обича своята жена/ жена си. = He loves his (own) wife.
Той обича неговата жена/ жена му. = He loves his (someone else’s) wife.