题目内容：

英语达人进来帮忙（关于定语从句）,
这里有三对句子：
1、The school where I study is very beautiful.
The school which/that I visited yesterday is beautiful.
2、The day when I was born is June 6th.
The day which spent with her is uncomfortable.
3、The reason why I was late is just an excuse.
The reason which/that I gave is just an excuse.
这三对句子的引导词为什么不一样啊?什么情况下用关系代词,什么情况下用关系副词啊?感觉分辨不清楚.能帮我详细分析一下这三对句子的句子成分吗?越详细越好（本人英语不好）.