Thread: What is the difference between мой and моя?

To my understanding they both mean "why"...but when should I use what?

Originally Posted by Valda

To my understanding they both mean "why"...but when should I use what?

Maybe "my"? мой is masculine моя is feminine. Both mean "my" or "mine".

Sorry, yes, I meant to type "my" Thank you!

The grammatical gender of these words depends on the object they refer to. Мой брат = my brother, masculine, моя сестра = my sister, feminine. Note that this is a grammatical and not just a biological distinction, so you also get моя машина = my car. But actual biological gender takes precedence, so you'd say мой папа = my father, even though the word папа ends in -а and is declined like a feminine word.

Bitpicker explained enough. But in case you haven't heard, some words end in Ь and you can't know the gender of the word until you look it up. Like the word словарь (dictionary) is masculine. Мой словарь. But тетрадь (notebook) is feminine, making it Моя тетрадь. These rules apply all the time, with adjectives too, and all possessive pronouns except for его (his) and её (her) which never change regardless of word gender and case.

Also keep in mind, adjectives work in the same way.

Красивая женщина (a beautiful woman)
Красивое здание (a beautiful building)
Красивый город (a beautiful city)
Москва большая (Moscow is big)
Москва большой город (Moscow is a big city)