English definition of “so”
REASON › used to say that something is the reason why something else happens: I was tired so I went to bed. Greg had some money so he bought a bike.
so (that) › in order to make something happen or be possible: He put his glasses on so that he could see the television better.
CONNECT › used at the beginning of a sentence to connect it with something that was said or happened previously: So we're not going away this weekend after all?