Regarding changing language and the usage of “nonplussed”: until recently, nonplussed was a word in British English. I think Americans assumed, without checking, and based on the components of the word, that it meant “unfazed.” (I first encountered nonplussed in the late 90s in the Harry Potter books.)
Certainly language changes over time, but this particular “change” is based on people completely making up a new definition based on a misunderstanding, and oh by the way, the new made-up definition is the complete opposite of the original one.
I’ll leave this to the professional linguists, but I’m unclear what advantage there is to one word meaning two completely opposite things. It’s particularly confusing to people learning English as a second language. It seems like the better practice would be to have two different words for each thing!
I maintain that “literally” has not had its meaning shift at all. It simply has been used more often to emphasize exaggerations. Consider:
“I was so tired that I could not get out of bed” is already likely an exaggeration. In reality, the speaker opted not to get out of bed.
“I was so tired that I literally could not get out of bed” is the same statement, with the same meaning. “Literally” adds emphasis by making it a taller tale. It also absolves the speaker of responsibility in a lighthearted way. “It’s not my fault I’m late! I was unable to leave my bed!”
Both statements are figurative, but neither would naturally include the word “figuratively” because the context is understood without it. I have never heard anyone argue that the first example, above, changes the meaning of “could not get out of bed,” but you add one word for emphasis and suddenly the argument is that the emphatic word had its meaning flipped? I don’t agree.
Those exasperated by “literally” in the second example may well have a point that the exaggeration is unnecessary and used too often in common speech. I happen to be guilty of that, agree with the sentiment, and have been working to remove absolutes and exaggerations from my speaking and writing.
It may be my limited experience, but I do not recall many or any uses of “literally” where “figuratively” would have been both natural and appropriate. If anything, I might suggest that “literally” is stepping in where “really” might work better.
