english grammar error

src/macos/simulate.rs

@@ -87,7 +87,7 @@ unsafe fn convert_native(event_type: &EventType) -> Option<CGEvent> {
     convert_native_with_source(event_type, source)
 }
 
-///cause all of button events contain coordinate which can be used when they be simulated.
+///cause all of button events contain coordinate which can be used when they are be simulated.
 ///so you don't need this fn when button press/release anymore.
 #[allow(dead_code)]
 unsafe fn get_current_mouse_location() -> Option<CGPoint> {