Let’s take a case in point. In the “men” thread, Dave wrote
The plural men is found in Old English and in other early-medieval Germanic languages. It undoubtedly goes back to proto-Germanic (i.e., the language or group of languages that gave rise to the modern Germanic languages, like English, German, Dutch, and Swedish). More specificity, no one can provide.
And I just now responded:
No, Proto-Germanic would have had *manni; umlaut came later.
Should I have said instead “Well, I can certainly understand how you could say such a thing; it’s a natural deduction. But in fact Proto-Germanic did not yet have umlaut (the raising of vowels due to the influence of vowels later in the word), and the reconstructed form would be *manni instead (the asterisk is what we use for reconstructed forms)”?
Because if I’m going to have to put on the persona of a kindly, patient high school teacher every time I respond, I’ll just stop bothering. There’s a reason I didn’t become a high school teacher.