1actually
2place
3classifier for houses, small buildings, institutions etc
4that which
5particle introducing a relative clause or passive
Examples
tā她suǒ所shuō说de huà的话shì是bù不zhēn shí真实de的。
她所说的话是不真实的。
What she said wasn't true.
这所大学是什么时候建的？
When was this university founded?
你是这所学校的学生吗？
Are you students at this school?