Mom and dad, your brothers and sisters, grandpa and your Aunt Millie. They’re all special people, and so there’s a rule just for them. In the plural form, the Italian definite article will appear before the Italian possessive adjective that refers to a family member or relative. For example, instead of saying "my brothers," you are literally saying "the my brothers."

The table below contains other examples:

USE OF ITALIAN DEFINITE ARTICLES WITH POSSESSIVE ADJECTIVES
Mio fratello è carino. (My brother is cute.)
I miei fratelli sono carini. (My brothers are cute)
Questo è tuo zio. (This is your uncle)
Questi sono i tuoi zii. (These are your uncles.)
Mia nonna è vecchia. (My grandmother is old.)
Le mie nonne sono vecche. (My grandmothers are old.)
Mio cugino è straordinario. (My cousin is exceptional.)
I miei cugini sono straordinari. (My cousins are exceptional.)