How do I disable hot key combinations

[Bret Busby]

How do I disable what I believe are named hot key combinations?

I am using UbuntuMATE linux 16.04.x, and, I can be typing text into a
form, and then, a half hour or so, of text typed in, suddenly
disappears and the screen hanges to show that something has happened,
and I am not sure what has happened.

I am losing about an hour's typing, each day, because of whatever is
happening, and, I am assuming that it is due to some inadvertent and
unwitting key combination.

The mouse keeps bringing up menu's in web pages, when it is not
supposed to be doing that, but that is another problem.

-- 
Bret Busby
Armadale
West Australia
..............

"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
 Chapter 28 of Book 1 of
 "The Hitchhiker's Guide to the Galaxy:
 A Trilogy In Four Parts",
 written by Douglas Adams,
 published by Pan Books, 1992

....................................................