英语作文时态问题：whenlet 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。
问题描述：
英语作文时态问题：when
let 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。
答
哦,是假设句式,假设情况的半句要用往后的一个时态（如果在“现在”的基础上假设,假设半句是“过去”时态,如果在“未来”基础上假设,假设半句是“现在”时态）
If there are something happening in our class(假设未来,则用现在时态）,she will know a lot of details than we will.
If there were something happened in our class(假设过去时态,则用过去的过去）,she could know a lot of details than we could.
后面那个句子不是假设句,是条件从句,没问题.