Hi everyone! The forum is a very amazing place for learning Czech! So I think I would like to ask any questions about Czech here rather than in my online discussing group as it is very inactive. So here is my question today: What are the differences between "si" and "se"? I can see there are a lot of Czech words such as "dávat si", "sedat si", "dívat se", "pouštět se"...but the textbook doesn't tell me what is the difference between "si" and "se". So, are the two words exchangeable? If yes, in what case? If not, then in what case? Many thanks for anyone who answer this question for me!