题目内容：

希望您能帮个忙.
et me give you an example.If there are something happened in our class,she could knew a lot of details than we were.请帮我找出这句话的错误和原因
我和我的朋友已经毕业,我要写一篇比较她和另外一个人的英语作文,在说道：when we go outside,she loves to buy a lot of things to showing off 的时候,这句话的语法是不是有错误?时态的错误?我分不清时态的转换和用法.