When I listen to the whole sentence, I hear "2anti" for the first word (or "2anta" in the case of a male), but when I hover over just that word, I just hear something like "2ant" or "2anth" whether it's male or female. Why is that?
Usually, at the end of a sentence and thus, also for standalone words, you do not pronounce a final short vowel.
Why does "أَنْتِ" get "تِ" at the end and not "تَ"? Does it have something to do with the following consonant "ر"?
When you are talking to a female: تِ , When you are talking to a male: تَ
Why isn't the yaa used here?
I assume that is because it is not calling to Rosa, but simply stating that she is her. "يا" would be used to address somebody, i.e. "Thank you, Rosa!".