KimmyDawn,
We all have words that mess with our minds. The ones you mention are not the ones that get me. For some reason I can't remember when to use an apostrophe after i t s. When is it proper...sigh. It goofs me up and makes me stop short when I'm typing and grr. I hate that.
Mine seem to be more about spelling than about usage. I was an English major in college - for what it was worth since I did not finish.
If it isn't one thing, it's another....hope I was correct in putting the apostrophe...sigh....=)
Leslie