Translation:He is a student, what about you?
The likely reason for the article "a" is that it wouldn't be grammatically correct in English to say "He is student...". Keep in mind that Chinese grammar rules aren't always the same as English grammar rules; it's impossible to always directly translate from Chinese and still get a grammatically correct sentence in English.
"ta" can mean he (他 ), she (她 ), or it (它 ). This shows you why you need to learn to recognize the characters. Many of the pinyin words have multiple meanings all represented by different characters. Similarly, pinyin words' meanings and characters change according to the tone used. Not an easy language to learn, but an interesting one.