I'm not sure where your friend was getting that information, or what small details he was referring to. Calling Objective-C from within Swift is remarkably transparent -- where you might have called `[foo bar:baz];`, you call `foo.bar(baz)`.

In some cases, wordy Objective-C names will get mapped to Swift's tidier conventions, but the public APIs are all documented in both languages, and Xcode's auto-complete is pretty good at helping you figure it out.