请帮我看看这句英语写的有没有错误,

题目

请帮我看看这句英语写的有没有错误,
I not only studied very hard but also did a lot of reasearch work about my major during my study years.

答案

Not only did I study very hard in my school years,but I also did a great deal of reasearch in my major.
理论没什么好说的,改成这样,符合英文的表达习惯.