It used to be that "momentarily" mean "for a moment" but now it's used to mean "in a moment" as well.
It used to be that "oblige" and "obligate" were treated differently, but now the former is almost completely unknown.
It used to be that the "silly" meant "carefree" or "young and innocent."
It used to be that "nice" meant "exact" or "precise."
It used to be that "literally" meant "really, really truly" but now it's just used for emphasis.
It used to be that people knew the word "pedantry" but now they seem to use "pedanticism."
Given the predominence in written language for confusion between "there," "they're" and "their," will the written distinction eventually vanish?
Call me a pedant, but I think some of these changes genuinely impoverish the language. But languages change, have always changed, and will always change, until they're dead.
Your core point is correct but your examples are pretty weak/wrong.
Momentarily has meant “in a moment” since the late 19th century. Sometimes (more commonly a couple hundred years ago) the word also means “at the current moment.”
“Oblige” and “obligate” still have different sets of connotations, but I really don’t think your case is very strong here, since their main overlapping senses, in which they’re roughly interchangeable, have been in common use for several centuries, perhaps since the words first arose. The word “oblige” is still extremely common, in my experience more common than “obligate” for this use.
“Silly” originally meant “pitiful” (in the modern sense; “pitiful” originally meant “full of pity for others”). From there, it transformed into meaning “unsophisticated” and then “feeble-minded” or “foolish.” The OED doesn’t have it ever meaning anything close to “young and innocent.”
“Nice” has had a very complex set of evolved meanings. It began meaning “foolish” or “ignorant”, but in the past 500 years has meant at various points “lascivious,” “ostentatious,” “elegant,” “fussy,” “refined,” “respectable,” “virtuous,” “appropriate,” “effeminate,” “lazy,” “fragile,” “modest,” “shy,” “intricate,” “subtle,” “precise,” “slim,” “trivial,” “dextrous,” “doubtful,” “tasty,” “pleasant,” “attractive,” “friendly,” &c.
Examples have never been my strong point, but even so, I suggest that more people use "pedanticism" than "pedantry," and I have rarely heard "literally" used in anything other manner than for emphasis.
But I suspect we are more in agreement than otherwise.
Maybe this is a difference of geography? I’m from California and go to school in Boston, and I don’t know anyone who uses “pedanticism.”
Anyway, I concede that literally is often used as an intensifier, even non-ironically. I like the end of that Slate article:
> The one sensible criticism that can be made about the intensive use of literally is that it can often lead to confusing or silly-sounding results. In this case, the answer is simple: Don't write silly-soundingly. Some usage books even bother to make this point about literally. Then again, most usage advice could be reduced to one simple instruction: "Be clear." But that would be the end of a publishing category.
It used to be that "oblige" and "obligate" were treated differently, but now the former is almost completely unknown.
It used to be that the "silly" meant "carefree" or "young and innocent."
It used to be that "nice" meant "exact" or "precise."
It used to be that "literally" meant "really, really truly" but now it's just used for emphasis.
It used to be that people knew the word "pedantry" but now they seem to use "pedanticism."
Given the predominence in written language for confusion between "there," "they're" and "their," will the written distinction eventually vanish?
Call me a pedant, but I think some of these changes genuinely impoverish the language. But languages change, have always changed, and will always change, until they're dead.