U.S Gov't

What have you learnt about American government? 
I have learnt about the three branches of the government: Judicial, legislative, executive. I have also learnt that Congress is made up of the House of Representatives and the Senate. I also discovered how a bill becomes a law. In addition, I learnt about the laws and the various things that the state and federal government share, as well as the things they don't share(reserved, concurrent, delegated).

What questions do you still have about U.S government? 
I am still a bit unclear on the separate roles of the judicial, legislative, and executive branches, and the differences between them. I'm also wondering about the courts, and the roles juries have to play as well as how the court system works.