someone "has" their birthday, that sounds strange to me
Don't we usually say, "it's someone's birthday today"?
Someone has birthday sounds strange to me
I asked around, it seems that it's ok... your version is accepted.
someone has is singular but their is plural how can that fit?
It's a non-specific pronoun. Someone is singular/ambiguous because we don't have information on their gender. So, unless you know that the "someone" is a boy or girl you would use "their" in the place of his/her
Yes, English is a crazy language, isn't it? We often use "their" instead of "his or her", and "they / them" instead of "he / she / him / her".
The audio on full speed sounds correct.
The audio on slow seems to drop the "u" sound on urodziny, making it sound more like family than birthday.
Could be my ancient ears of course.
Why isn't it "urodzinę"? Isn't it the object in the sentence?
It's the object, but it's also plural non-masculine-personal, so it stays the same.
Right. It had slipped my mind that it was plural/mas.