Note: this is a "vintage" tip for older computers and/or systems.
From any program command space sets the language to the next script and command option space sets the language to the next language in the current script. If you find the language changing unexpectedly check the software you use (eg Photoshop) doesn't also use these combinations.
Remove associated resources if you don't need them to stop this happening accidentally. Open the system file and remove the unwanted keyboard "files". (Standard warnings for modifying the system apply).
I usually write a blog post about once a week. The latest post can be viewed here: Avoid Microsoft: If you don't really like computers much you could make things a bit better for yourself. (posted 2024-12-04 at 12:05:50). I do podcasts too!. You can listen to my latest podcast, here: OJB's Podcast 2024-08-22 Stirring Up Trouble: Let's just get every view out there and fairly debate them..