sin

sin means "new" or "again." It's almost always clear from context which of those two sin means. I recommend paying attention to sin's usage in the wild to try to figure out if it's ever ambiguous between new and again. The reason why it isn't is because the difference between those two concepts isn't very far. It doesn't matter if you've done it before. In toki pona, something can be new even if it isn't the first time it's happened.

sin can mean a lot of things, and that range of possibility is given by explaining what something is new to. children are new to this world, toki pona learners are new to toki pona communities, a new brand of soda is new to the Free Market Economy which we all Love So Much, etc. These can all be sin!