When a specific "incorrect" usage of a phrase becomes--and stays--way more common than the "correct" usage, it stops being "incorrect." Analogously, we can correctly use the token "assert" as an identifier in Java 1.0, but not in Java 1.5.
Language does change, but empirically these things don't seem to be decided by simple majorities. "Ain't" has been very common for centuries and is still seen as a solecism.
The threshold for change seems to be when people who know the correct form opt not to use it, because it seems too fussy. I would say that's happened now with trailing prepositions and split infinitives. We aren't near that threshold yet with "begging the question" though. We may never be, because it's still needed for its original meaning.
Split infinitives were never wrong to begin with. The farcical objections to them began in the late 19th century, crested in the 20th, and have subsided in the 21st. Some modern style guides even recommend them!
I thought the same thing, but Wikipedia reports that although in Old English some verbs were formed with "to" (I didn't even know that) splitting them was never done.
It is different. You are talking about an observation made about a prior iteration of English (descriptive). I am talking about arbitrary rules created long after the development of the current iteration of English (prescriptive or, more accurately, proscriptive).
I want to blindly accept that argument but I can't. Those who choose to casually break the rules of the language need swiftly to firmly be reprimanded.
The trailing preposition is different because it was always good Old English and only recently proscribed. And what did we ever ban something our ancestors were so loyal to for?
' becomes--and stays--way more common than the "correct" usage '
OTOH, nearly each time there's a post with the incorrect usage, there's also a comment or two of correction.
Which begs the, er, which raises the question, how do you know when a certain usage has become more common? You can't just look at your own social circle (or HN, or whatever) and decide that's how everyone uses it.