is she a teacher and is she priya i want to ask that teacher vale sentance me "a"laga hai to priya vale sentance me "a"kyu nahi laga

Because priya is a name and it's a proper noun and we don't use any article with proper nouns. Specially then, when it's a name of any boy, girl, place . Ex:- We never write the Patna, the sita, the ram, the delhi. It's a wrong process for writing.