In `runBlocking()` example, you may have noticed that the getValue() function is also defined with the suspend keyword.

The reason is that it calls delay(), which is also a suspend function. Whenever a function calls another suspendfunction, then it should also be a suspend function.

If this is the case, then why wouldn't the main() function in our example be marked with suspend? It does call getValue(), after all.

Not necessarily. getValue() is actually called in the function passed into runBlocking(), which is a suspend function, similar to the ones passed into launch() and async(). However, getValue() is not called in main() itself, nor is runBlocking() a suspend function, so main() is not marked with suspend.

If a function does not call a suspend function, then it does not need to be a suspend function itself.

Tips ​

In Android Studio the suspend functions are have an icon in the left gutter.