Cognitive Impairment

I've noticed in the past year that when I'm writing on the computer I sometimes make very odd word substitutions. I'm guessing it's age related. I decided to keep a list of the words, because I know enough about how the brain organizes language to know that different kinds of substitutions -- say words that sound alike vs. words that have a similar meaning vs. words that use the same letters just in a different order vs. words that have a similar structure vs. words that are part of the same category of objects (for example, trees) -- are the result of glitches in different areas of the brain.
Anyhow, here's my list. See if if you can make anything of it. I can't.

or FOR are
kind FOR got
bit it FOR be it
buy FOR pay
do FOR to
suggestively FOR successfully
again FOR aging (heh!)
pines FOR palms
think FOR thing
important FOR appropriate