Why is the word Forward appearing in green at the bottom right and corner of my computer screen?

I was experiencing the same thing with my Thinkpad laptop (a few years old) recently. It was really perplexing until I figured out the word appeared whenever I hit the "forward" button in the lower right had corner of the keyboard (there are two buttons with what look like miniature screens, one with a arrow pointing left and one with an arrow pointing right. Hit the right arrow and the word "forward" appears, hit the left arrow and you'll get "backward.") I never even realized this was a "forward" button until I did an internet search--I'm not the most tech savvy computer user. I don't recall seeing these words appear on my screen before even though I've had the computer for awhile--maybe I'd never accidentally hit these buttons before or maybe the cat I just acquired "reprogammed" my computer while it was walking on the keyboard.

The words only last a few seconds on my screen--if the word isn't going away on your screen maybe the key is jammed.