For example, if I lived in Wyoming in 1901 and I read in a newspaper that some guy from NY named "Roosevelt" was going to be the vice president, would me and all my fellow Wyomingite's go 8 years pronouncing the first syllable of his name like a "rooster" instead of "rose?" Who would even correct us if we were all wrong?
This is a fun question and I have a doozy of an answer for you.
No one knew if they were right or wrong. Simple as that.
And let me tell you, you're going to need to change your thoughts on what correct pronunciation is anyway. Sure, arguably names have a correct pronunciation in that people say their names a certain way. But that can easily drift or change, and that's assuming people learned from their parents how to correct their names correctly to begin with.
So when we talk about right or wrong, first we need to talk about linguistic descriptivism versus prescriptivism. Prescriptivism is a branch of linguistics that is largely dead, but it is about declaring certain rules or usages to be proper or correct. But that begs the question--what is correct?
That's where descriptivism comes in, in which linguists describe phenomena in language without casting aspersions as to whether it is right or wrong. It just is. If you can understand meaning, arguably, language has done its job whether it was done correctly or not.
So back to my point. First of all, how do we know how people even pronounced things in the past? Well, we have a couple of hints. The first is that we know how things were pronounced based on regular linguistic rules that teach us how sounds evolve. So we can reconstruct with reasonable confidence how things sounded based on how they sound now. We can't always be 100% sure, but we can be fairly confident.
But here's our little cheat code when it comes to English.
I haven't studied this in other languages so I cannot speak to how this works with them so here's all my caveats: don't say that this is unique to English or anything silly like that, don't post on TIL and tell people that English is special blah blah whatever.
But because there is a discrepancy between how English is spelled and how it is pronounced, we can use historical misspellings to see how certain words were pronounced. We can also use poetry with rhyming couplets, but misspellings are a treasure trove here. It allows us to glimpse what learned folks were attempting to say, even if it was at odds with how those things were spelled. And that's extremely helpful.
In summary though, no one necessarily would have known. Roosevelt might drop by Wyoming and say his name and you'd nudge your neighbor and go, "Ah, that's how he says it!" You might have a tin ear and never realize you've been saying it wrong.
But one thing is for certain. Shakespeare was not terribly serious about how to spell his name so I'm only 80% sure how he'd pronounce it.
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