And people who use 'myself' instead of 'me' because they think it makes them sound clever.
Beaten to it (and by crazy_legs, too).
I see it lots in emails from apparently educated people. Sometimes I wonder that they're scared of the word "me". They're clearly not as intelligent as they woulkd like to think.
Oh, and the incorrect use of "would", "should" and "could". you know, as shown on the overblown sentence so many people use as a sign off to their emails: "I would be grateful if you could send that to me." My immediate response is to think "I could. But why should I?". Of course, what they really meant to write was "I should be grateful if you would...", thus enabling - and requiring - the recipient to send the item.
The other, and it's much more prevalent in The North than The South, is the overuse of the progressive: "Is anyone wanting anything sending in the post?". "Yes, I'm wanting...." means "I'm giving you a running commentary on what I want without actually telling you that I want it". FFS. Idiot Northern types. Also used by the obesqueous when providing thanks "Thanking you". Arrgh.
Little of this affects (note, not "effects") our understanding, but that's only because some of use have the brains to understand how it ought to work, but also have to compassion to make allowances for the illiterate and imbecilic.