Anatoly Vorobei writes:
Many years ago, my mind was blown by reading Otto Jespersen’s Modern English Grammar On Historical Principles. I read/skimmed mainly Part I: Phonetics, where Jespersen slowly, fascinatingly and painstakingly goes over the phonetical changes that occurred in English […], including the Great Vowel Shift as well as changes that came after it. He doesn’t just list the principal changes, he discusses at length when they occurred, approximately, what they were caused by, when this is known, and what were the exceptions to them. He gives many examples of words that underwent the changes or exceptions that didn’t, and for the latter he discusses the reasons why (that was one of the most interesting aspects of the book – realizing that sound changes are not always as completely universal in a language as I’d naively thought).
I want to find this book again, […] [b]ut before I even do that, I’d like to understand if I should really be looking for a different book instead. After all, Jespersen wrote something like 100 to 70 years ago. Perhaps many of his explanations are considered outdated by now; perhaps there have been much better books of this kind. I wouldn’t know – I’m not a linguist and my interest in this is amateur. If you know anything about how well his work stood the test of time, or about newer books of this kind I might be interested in, would you please let me know? I’d like to emphasize though that I’m not simply looking for, say, a concise one-volume “History of the English Language”, of which there are dozens, many doubtless excellent. I looked at a few and their phonetics sections mainly listed the important sound changes that occurred, with a few examples. They lacked the obsessive “deep-dive” into many examples, exceptions, discussions of sources and methodology, etc. that I remember loving in Jespersen.
I don’t know the answer (the history of English was not my specialty), but it’s a good question, and I thought some of my learned readers might know, so I’m passing it along.