I know people who say seen for saw. They often use double negatives, too.
Those people don't have the best education and they aren't encouraged to speak correctly, so I understand their mistakes.
But what I especially don't like -- and don't understand -- if people who know better but use English pretentiously.
They'll say something like, "Prior to the soiree, I engaged ... "
Damn it! Say, "Before the party, I did ... "
I wonder who they're trying to impress. It certainly isn't me.
Also, you can say that English is polluted by double entendres.
For example, you can't say Oral Roberts or Oral Hershiser without some fool giggling and saying, "How about their cousin -- Anal?"
Thank you, good sir, for bringing the level of discourse down to the level of a gradeschool playground.