Hi Bob
There certainly could be a lot of sources of this type of problem so more details on your system/software might help e.g. OS used and which language version, PS version and if you have a particular language version, do you have a non-US standard keyboard, etc
As an example problem, I have a Mac and occasionally use the built in Mac software to have the keyboard take input as if the keyboard were a different type (e.g. a non-US keyboard). I use it for debugging others problems yet it gives access to characters only easily available in that native language. I found out the hard way that when I have a variety of those different keyboard sources set up, there was also a default keyboard shortcut "Cmd + Space" that would switch to the next keyboard input source (another language) and would occasionally start adding in foreign characters. Unfortunately that was also a common PS keyboard shortcut that I always used with PS for zooming in and it was a real PITA. I fixed this by disabling that particular Mac keyboard shortcut.
Most likely this is not your issue yet if you want more targeting suggestions/debugging, a lot more details from your end would be real helpful.