I don't want to check if the key was pressed.

I want to check if the TAB function of the keyboard is activated (this could also happened before the engine starts and so key_hit would not detect it).

When it is ON, you don't have to press Shift to write capital letters.

In my game the user have to write small letters but when TAB is activated this will not work. So I want to tell the player that he should deactivate it but I don't know how to check if it is ON.