Writing prompt: My Classmate

Student essay:
You may want to ask why my deskmate is lovely.So let me tell you!
First,my deskmate has a medium height with big eyes and short black hair.He's so thin that I can even see his bones,but I think he's handsome.He is always well-dressed,so he's always neat.
Second,he has positive personalities.He is smart and talkative,so he always help me with my maths.Although sometimes he's naughty,he's warm-hearted.I regard him my best deskmate.
At last,I want to say something about his hobbies.He is crazy about cartoons and his favourite cartoon is One Piece.He enjoys playing basketball as well,and I think he is quite cool when he is in the basketball field.And he said that doing sports is good for your health!
I will always share my happy and sorrow with you--my deskmate!

Corrected essay:
You may want to ask why my deskmate is lovely. So let me tell you!
First, my deskmate has a medium height with big eyes and short black hair. He's so thin that I can even see his bones, but I think he's handsome. He is always well-dressed, so he's always neat.
Second, he has positive personality traits. He is smart and talkative, so he always helps me with my maths. Although sometimes he's naughty, he's warm-hearted. I regard him as my best deskmate.
At last, I want to say something about his hobbies. He is crazy about cartoons, and his favourite cartoon is One Piece. He enjoys playing basketball as well, and I think he is quite cool when he is on the basketball field. And he says that doing sports is good for his health! I will always share my happiness and sorrow with him—my deskmate!