Why am I going on about this again? Well, Gil commented that the vagaries of English spelling makes it difficult to know how to pronounce unfamiliar words, especially in another dialect region. You can tell that someone is not a native New Yorker when he or she pronounces Houston Street like the name of the city in Texas. In Manhattan, it's "Howstun" with the stress on "How."
Gil then asked if my last name was pronounced like the ch in chair or the ch in Chanukah. (Actually, I've never met a non-Jew who pronounced that sound in Chanukah, correctly. My favorite mispronunciation of all time was the music teacher in a Pawtucket, Rhode Island high school who told the band they would be doing some "chunOOkuh" music. The kids thought he was going to teach them some Native American songs--until he started to play, "I Had a Little Dreidel." Why he chose that ditty instead of the hymn sung on that holiday, I don't know. But, I digress.
Back to my surname--which is actually my husband's and comes from the Polish Czajka. Many people pronounce the ch as sh. I don't know why, but almost everyone does. When you combine that mispronunciation with r-dropping as some Rhode Islanders do, you get an interesting switch in names, as illustrated in the embarrassment Bill and I suffered at a wedding dinner about 50 years ago. In order to find what table you were supposed to be seated at, you had to find your name tag among a table laden with such tags. However, we couldn't find our name tag. Neither could anybody else. We,of course, wondered, had we sent back the response card? Were we disinvited? Finally, only one tag was left. It was labeled "Mr. & Mrs. William Shaker." An er at the end of a word is "uh" in r-dropping accents. So, Chaika became Shaker. Also, under some circumstances, a final "uh" becomes pronounced as "err," as in "sofa is" becomes "sofer is."
When we lived in Foster, Rhode Island, in a very rural area, my kids were teased as being "salt shaker" or "pepper shaker", the latter being pronounced "peppuh shakuh."
The reason that a ch is mispronounced as a sh has nothing to do with r-dropping, however. The ch is actually two sounds: a t followed by sh. If you fail to pronounce that initial t, you end up with sh. If you know any French, you note that in that language, a ch spelling is always pronounced sh. In words borrowed from French to English after the 15th century, we pronounce chef, cherie, and chaise as sh. However, words borrowed into English from French before the 15th century, we have the English ch, as in chief, cherry, and chair. French used to pronounce ch as English does. However, in the 14th or 15 century, French speakers en masse failed to start the ch with the t, so that ch became sh.