Possessive pronouns are determined by the owner, 1st, 2nd, 3rd person singular / plural, and by the gender and number of the thing possessed.
person singular / feminine - singular
É a minha casa. (This is my house.)
person singular /feminine - plural
São as minhas casas. (These are my houses.)
person singular / feminine - singular
É a tua casa. (This is your house.)
person singular / Maskulinum - Singular
É o teu problema.(This is your problem.)
person singular - Plural / feminine - singular
É a sua casa. (This is his house.)
person plural / Maskulinum - Plural
São os nossos problemas. (These are our problems.)
In the following exercise the person is given with the unstressed personal pronoun: eu, tu, ele, ela, você, nós, vocês, eles, elas. In other words this way:
eu, feminine - singular
É a minha casa. (This is my house.)
eu, Femininum - plural
São as minhas casas. (These are my houses.)
tu, feminine - singular
É a tua casa. (This is your house.)
ele / ela / você, feminine - singular
É a sua casa. (This is her house.)
nós, Maskulinum / Plural
São os nossos problemas. (These are our problems.)
However in the case of possessive adjective the gender and number of the thing possessed is not indicated, because in this case the gender and number is obvious. Furthermore in interrogative sentences we have to times qual / quais, what is actually which. However we translate with what.