Possessive pronouns in Ukrainian show ownership or possession. They must agree in gender, number, and case with the noun they describe.

Basic Forms

	Masculine	Feminine	Neuter	Plural
My	мій	моя́	моє́	мої́
Your (singular)	твій	твоя́	твоє́	твої́
His, its	його́*	його́	його́	його́
Her	її́*	її́	її́	її́
Our	наш	на́ша	на́ше	на́ші
Your (plural)	ваш	ва́ша	ва́ше	ва́ші
Their	ї́хній	ї́хня	ї́хнє	ї́хні
One’s own	свій**	своя́	своє́	свої́

Example sentences :

Він мій ба́тько. – He is my father.
Вона́ моя́ ма́ти. – She is my mother.
Вони́ мої́ батьки. – They are my parents.
Мій брат і твоя́ сестра́. – My brother and your sister.
Ва́ші і на́ші діти. – Your and our children.
Його́ син студе́нт. – His son is a student.
Його́ дочка́ вчи́телька украї́нської мо́ви. – His daughter is a teacher of Ukrainian language.
Як зва́ти її́ бра́та? – What is her brother’s name?
Зві́дки ї́хні батьки́? – Where are their parents from?

When to use “свій”?

The pronoun свій means "one’s own." It is a reflexive possessive pronoun, used when the subject of the sentence possesses the object of the action. Depending on the context, "свій" can mean my, your, his, her, our, or their, but only when the object belongs to the subject.

1. Reflexive vs. ordinary possessives

Свою́, свій, своя́, своє́, and свої́ refer back to the subject of the clause, showing that the subject owns or is directly associated with the object. Ordinary possessives, such as мій, твій, наш, ваш, його, її, and їх, indicate possession by someone other than the subject or are used when emphasizing or contrasting ownership. 

Example (first-person subject):

Я чита́ю мою́ кни́гу. – I read my book.
Я чита́ю свою́ кни́гу. – I read my book. 

Both are correct, but "свою́" is more natural when the possessor is the same as the subject.

Use мій / мою́ only when you contrast or stress ownership:

Я чита́ю мою́ кни́гу, а не твою́. – I’m reading my book, not yours

2. Second-person subjects (ти / ви).  It’s preferable to use “свій”.

Ти ремонту́єш свій комп’ютер? – Are you fixing your computer?

3. Third-person subjects (він / вона / вони)

Вона́ лю́бить свою́ ма́му. – She loves her (own) mother. (Reflexive)
Вона́ лю́бить її ма́му. – She loves her (someone else’s) mother. (Refers to a person or thing that belongs to someone else.)

4. Reflexive pronouns in subordinate clauses

Свій must refer to a subject in the same clause. If the possessed noun is in a subordinate clause with a different subject, use ordinary possessives:

Вона ка́же, що її́ кни́га ціка́ва. – She says that her book is interesting. (Її́ is used because the book belongs to the subject of the subordinate clause.)

When NOT to use "свій"

Use ordinary possessives (мій, твій, його, її, наш, ваш, їх) when the object does not belong to the subject, or when you are simply identifying or describing objects without an active action.

Це моя́ кни́га. – This is my book. (Ordinary possessive, standard)
Це сво́я кни́га. – This is my book. (Reflexive is unnatural here)

Declensions of possessive pronouns

“Мій“, “твій” and “свій” are declined with the same endings (e.g. моя, твоя, своя; моїм, твоїм, своїм, etc.).

“Наш” and “ваш” are declined like the adjectives of the hard group.
“ї́хній” is declined like the adjectives of the soft group.

Note: “його” and “її” are never declined. Examples:

Його́ телефо́н у його́ су́мці. – His phone is in his bag. (nominative + locative, unchanged in all cases)

	masculine	feminine	neuter	plural
Nom	мій	моя́	моє́	мої́
Gen	мого́	моє́ї	мого́	мої́х
Dat	моє́му	мої́й	моє́му	мої́м
Acc	мій, мого́	мою́	моє́	мої́х, мої́
Ins	мої́м	моє́ю	мої́м	мої́ми
Loc	(prep.) + моє́му, мої́м	(prep.) + мої́й	(prep.) + моє́му, мої́м	(prep.) + мої́х