Choosing sides

Since both Iron Man and Captain America have such strong personalities, none of them will give in "“ they will definitely clash. As said in here, there are characters of which we may already know what sides they will pick.

Sure enough, the main event of the MCU's Civil War is expected to be, just like in the comics, a fight between Iron Man and Captain America. However, given the teams and even the relationships between the members of the teams, it is also expected that skirmishes will take place throughout the entire movie. Who will win in the end is anybody's guess.

Death

Crossbones appearing in Civil War can mean only one thing for the comic book fans "“ that Steve Rogers will meet his end at the end of the movie, his place as Captain America being taken by Bucky Barnes/Winter Soldier.

But this isn't the likeliest way in which the movie will end, since Chris Evans will appear in both installments of the Infinity War. Unless, of course, his death in the Civil War won't be a permanent one, just like in the comics and just like almost any other death in the MCU.