请帮我看看我写的英语句子有没有错误（初二）

题目

请帮我看看我写的英语句子有没有错误（初二）
Vince said,"I am trying to sleep ,but I hear a man is singing loudly,So I can't sleep .Do you know who is he?"Hector said,"Oh,sorry this is me.""you sing very well.but would you mind not singing so loudly?""not at all.I won't do it again.So vince could go to bed.
整篇用的是过去式,但说的话里要不要用过去式呢,有没有错误的地方,请帮我改改吧,

答案

but I hear a man (who)is singingloudly,
who is he-who he is和this is me-It's me
you sing very well-you sang very well.