A:Answer Hopefully this helps you!
You did not state what operating system you are using, so for Windows it is as follows:
By default ALT-LEFT SHIFT is used to switch between languages. Far too easy to press these by mistake, especially if you're like me and prefer the keyboard to the mouse.
To change this, go into Control Panel/Regional Settings/Languages/Details and there is a button that allows you to configure the shortcuts to switch languages - I just disable it altogether.
You may also want to disable automatic detection of languages in Word (Tools/Languages), I think this may switch the keyboard layout to match the detected language.