I figured out why this goes on so frequently. There’s a keyboard combination that switches languages. Mine was set to Ctrl-Alt which gets hit occasionally. There’s two ways to turn it off
1. Near the bottom right of the screen is an icon of a keyboard. Left click and select US keyboard if it’s set to French. This turns it off but it doesn’t prevent it from getting switched again.
2. The permanent fix is to disable the key combination. There’s two ways to do this. Right click on the keyboard icon and left click Settings. Select the “Advanced Key Settings” tab. Click the “Change Key Sequence” button and select “not assigned”. Click OK a few times and you’re done.
If you cannot locate the keyboard icon you can get at this through the control panel. Go to Regional and Language control panel. Select the keyboards and languages tab and click the change keyboards button. This takes you to the language settings described in step 2 above.
(I guess I ask a lot of questions because it nearly drove me nuts.)