I've been following Sue's Red Marker Blogathon with great interest, and especially enjoy reading the comments. A lot of the common errors one sees have been covered, so I have little to contribute.
Among the many 'englishes' we encounter, though, the errors made by working class people who have just a smattering of the language, are often rather endearing.
The SRE's caddy sends him an SMS one morning, saying ' Call me at this nambar.'
A long ago employee had to take her daughter for a Hex-ra ( an X-ray).
According to my driver, the substitute car has many 'poblem.'
And last, but most definitely not the least, I had the plumber in last week, and among other items on his bill, this one stood out: 'Shit cover.'
Could anything be possibly more appropriate for a toilet seat?