I have a long list of "pet peeves" with our beloved langauge. (Perhaps, as an American, I can lay blame on the Brits )
Two that have come to mind most recently involve more the SPOKEN word.

It irritates me to hear "professional speakers" pronounce the word introduce as if it was spelled inter-duce. The dictionary lists this as an alternate, acceptable pronunciation. But it still strikes me as wrong.

In a similar way I am upset when the word "envelope" (the noun, not the verb) is pronounced as though its spelling were: on-velope.

Am I overly-sensitive? Does this strike anyone else? (Should someone else strike me?!)

"I am certain there is too much certainty in the world" -Michael Crichton