I have finished reading it.I finished reading it.这两句话有什么区别吗?第一句语法有问题吗

问题描述:

I have finished reading it.I finished reading it.
这两句话有什么区别吗?第一句语法有问题吗

语法没有问题
前者:我已经看完了
后者:我看过了