Fix typos in comments.

RxSwift/RxSwift/Event.swift

@@ -19,7 +19,7 @@ import Foundation
 *       >> error: unimplemented IR generation feature non-fixed multi-payload enum layout
 */
 public enum Event<Element> : Printable {
-    // Box is used is because swift compiler doesn't know
+    // Box is used because swift compiler doesn't know
     // how to handle `Next(Element)` and it crashes.
     case Next(RxBox<Element>) // next element of a sequence
     case Error(ErrorType)   // sequence failed with error

RxSwift/RxSwift/Observables/Observable+Concurrency.swift

@@ -14,7 +14,7 @@ import Foundation
 // or return result to main thread.
 //
 // `observeSingleOn` is optimized for that specific purpose. It assumes that sequence will have one element
-// and in cases it has more then one element it will throw an exception.
+// and in cases it has more than one element it will throw an exception.
 //
 // This is a huge performance win considering most general case.
 //

RxSwift/RxSwift/RxResult.swift

@@ -154,7 +154,7 @@ public let SuccessResult = success(())
 // lift functions
 
 // "Lifts" functions that take normal arguments to functions that take `Result` monad arguments.
-// Unfortunatelly these are not generic `Monad` lift functions because
+// Unfortunately these are not generic `Monad` lift functions because
 // Creating generic lift functions that work for arbitrary monads is a lot more tricky.
 
 func lift<T1, TRet>(function: (T1) -> TRet) -> (RxResult<T1>) -> RxResult<TRet> {

RxSwift/RxSwift/Scheduler.swift

@@ -31,10 +31,10 @@ public protocol Scheduler: ImmediateScheduler {
 //
 // It's probably best to make sure all of the errors have been handled before
 // the computation finishes, but it's not unreasonable to change the implementation
-// for release builds to silently fail (although I would not recommended).
+// for release builds to silently fail (although I would not recommend it).
 //
 // Changing default behavior is not recommended because possible data corruption
-// is "usually" a lot worse then letting program to crash.
+// is "usually" a lot worse than letting the program crash.
 //
 func ensureScheduledSuccessfully(result: RxResult<Void>) -> RxResult<Void> {
     switch result {