I don’t know. I wasn’t saying that there definitely was a word that couldn’t be used to start a sentence.
I was saying, however, that in order for the riddle to hold true, the word would have to be pronounced differently in ALL CASES in which it is capitalized, including the beginning of a sentence. I’d be willing to guess that any word one could come up with could be used at the beginning of a sentence in both cases of the word’s meaning.
The only type of word that would fit the riddle criteria would be one that cannot be used at the beginning of a sentence in the “lowercase meaning” instance. Like you said, I don’t think this is possible.
“What is the only word in the English language that changes pronuciation when you capitalize it?”
I don’t think the riddle says the word has to change pronunciation every time you capitalize it. It doesn’t even mention sentences, so I think that’s just riddle gardenpathing.
Polish/polish, Nice/nice, Reading/reading- all sound good, and I can’t think of any more.
Rainier is an interesting one since, when capitalized, it can be pronounced two ways, neither one the same as the lowercase word (the other is Prince Rainier).
But there’s lots of these capitonyms, although most have the capitalized form as the name of a person or place. Examples: Menachem Begin/begin, Reuben Askew/askew, Worms (Germany)/worms, Messier (hockey players)/messier.
I find the ones that are not the names of people or places to be more interesting. Examples: Junker (Prussian nobleman)/junker, Ewe (African ethnic group)/ewe, Tang (Chinese dynasty)/tang.