Use just a single key to switch languages in Windows
If you happen to use a second or more languages in Windows, you know that you are able to switch languages using a keyboard shortcut, normally Alt+Shift.
If you switch languages often you may prefer to use a single key instead of a combination. Windows 10 provides this option at Control Panel’s “Text services and Input Languages” > “Change Key Sequence”, where you can define the Grave Accent to be your Switcher.
If you are not on Windows 10 you can download freeeware such as SharpKeys to remap Grave Accent, assigning to it the combination of Alt+Shift.
Check also this page with the best free keyboard tools to remap, customize and enhance your keys.