What a fun thread, which seems to weave through several topics
1) Pronunciation. I grant mispronouncing "pronunciation" is awkward, but mispronouncing "err" in "To err is human" is also embarrassing. Here in the States, thanks to Penn State we've had our fill of news about pedophiles, but all the newsmen mispronounce "pedophile". They use a long E for other common words with the same root, like "pediatrics" or "orthopedic", but they can't handle "pedophile". In theory "conduit" ought to be a two-syllable word, like "biscuit" and "circuit"; has anyone ever heard it pronounced that way? (I've seen this pronunciation in dictionaries, but I never actually heard it.)
2) "Ax" for "ask" Certainly in the past "ax" was perfectly good English; after all "ask" and "ax" come from the old English "Axian"
"oh mother oh mother the daughter replied, I shan't do this thing that you ax, I'm willing to pay a fair price for the tea, but never no threepenny tax"
3) Misheard but accepted. My moniker comes from an old song, which we always sang as "Airymouse Airymouse fly over my head, and you shall have a piece of my bread". Surely the real word was "reremouse"
4) Misspoken. Richard Chase told me that in the old song Lolly-tru-dum he had changed "chattering tongue" to "flattering tongue". Some singers have adopted his change, but "chattering tongue" was used by Shakespeare in The Taming of the Shrew.