Is it possible to arrange a tournament of 12 players with each teaming with each other once and competing against each other twice? If there are twelve players, and each player is to be on a team of two with every other player exactly once, and also ends up competing against every other player exactly twice in 2V2 play, can such a tournament arrangement be made? In a similar question \- an answer beyond my comprehension is affirmative for 8 players under similar conditions, but it's beyond me how to apply the answer to 12 players. Cheers!

Yes, such a tournament can be made. It is called a Whist Tournament Schedule.