All you have to do is get over named parameters, square bracket message passing, and overall verbosity, and you know enough to read/understand Objective-C code.
If you can get past those three differences, Objective-C is remarkably similar to Java and other OOP languages.
Personally, I love the verbosity. The code pretty much just explains itself.
Swift is a welcomed change though. I'm very optimistic and excited about the future of iOS going forward.