What was written was not a reflection of speech. Not until Mark Twain did that happen. There are differences, even large differences, even now. But we put words on the page in imitation of speech far more than even our recent ancestors did. It didn't all suddenly turn around with Clemens, and formal conventions persist. Light or humorous writers imitate vernacular and politicians flirt with it for effect, but no one talks like a legal brief, an academic paper, or even the most modern (that is to say, instantly out-of-date) liturgies.
Still, there was some similarity of expression, and looking closely at earlier writing can show with some clarity how English has changed in the last one hundred and fifty years. Reflecting on this can give us some insight into understanding why Shakespeare (1600) now eludes us, and Chaucer (1400) can be read only with notes.
The painter George Healy, writing in the 1860's about going to Paris in the 30's.*
I knew no one in France, I was utterly ignorant of the language, I did not know what I should do when once there, but I was not yet one-and-twenty, and I had a great stock of courage, of inexperience - which is sometimes a great help - and a strong desire to be my very best.We would say I didn't know anyone in France, or, if avoiding the contraction, did not know. Similarly, though utterly ignorant is understandable to us, and we use both words still in subtly different contexts, very few would write that, unless purposely affecting a more ornate style. We replace should with would, and when once there would likely now have an I got added to it, and might drop the once. I was not yet would be I wasn't even, or I was not even, or perhaps hadn't turned would be substituted. One-and-twenty would be used only for effect now, to suggest a folk song or poem. We might use a half dozen other words before we got to stock of courage, but from there our phrasing would be much the same, except that we would say do my very best instead of be. Also, the quote is only one sentence, with many commas. Even I would likely break it up, and I would lean more to the older style than most others these days.
*The quote is from David McCullough's The Greater Journey: Americans in Paris, which I am liking very much.