title_body: Should I use “double o” in Toki Pona?
upvoted_answer: The book by jan Pije and jan Lope says:
  
  We've learned how to address people and how to make commands; now let's put these two concepts together. Suppose you want to address someone and tell them to do something. Notice how one of the o's got dropped, as did the comma.
  jan San o, ... - John, ...
  ... o tawa tomo sina! - ... go to your house!
  jan San o tawa tomo sina! - John, go to your house!