Questions & Answers about La mia vita privata non ti riguarda.
Could I use propria instead of mia in this sentence?
Is ti a direct or indirect object pronoun in non ti riguarda?
It is a direct object pronoun. The verb riguardare (to concern, to regard) is transitive, meaning it takes a direct object without a preposition. Just like in English where it 'concerns you' (not 'to you'), Italian uses the direct object pronoun ti.
Why do we say la mia vita with the article la, instead of just mia vita?
In Italian, possessive adjectives almost always require a definite article before them. The main exception is with singular, unmodified family members (like mio fratello). Since vita (life) is not a family member, you must include la.
Why does the adjective privata come after vita?
Descriptive adjectives that categorize or define exactly what type of thing you are talking about usually follow the noun in Italian. Since privata defines the specific kind of life (as opposed to a public life), it naturally goes after vita.