Something I was writing recently included the phrase "They aren't going to disappear anytime soon." I was a bit unsure about whether to write "any time" or "anytime", so I looked that up and found that either is apparently acceptable in adverbial contexts.
However, I discovered something else that interested me: it seems that, regardless of the spelling, the expression "not ... any( )time soon" only became frequent fairly recently. Here's the relevant Google Ngram Viewer chart (with smoothing of 1):
You can see that there's a huge increase in the use of this expression starting around 1975 or so, only a short time before the spelling "anytime soon" overtakes "any time soon" in American English (the spelling "any time soon" appears to have been more common in British English texts as of 2008).
I'd like to know how people used to express this idea, but I'm not sure how to find out.
The alternative phrasings I could think of off the top of my head were "(are) not about to disappear", "(will) not soon disappear", and "(will) not disappear soon".
The expression "not about to disappear" seems to be only a bit older than "any( )time soon". The Google Ngram Viewer shows a steep increase starting around 1960, with only a few, possibly false hits before then (smoothing of 1):
There doesn't seem to be great data for "not disappear soon", but I think the Ngram Viewer seems to show at least that this expression was not much more frequent in the past than it is today (smoothing of 1):
The chart for "not soon disappear" is more promising in that it shows greater frequency, but it's difficult again to interpret the trends because there seems to be a lot of noise (even with a "smoothing" of 3):
So at the moment, I'm guessing that someone from before 1900 might have written my phrase as "They will not soon disappear", but I'm not sure if that would have been the most natural phrasing or if there's some other synonymous expression that I have forgotten about (or that is no longer used). It doesn't sound quite right to my ears, but I'm not sure exactly why.
Can anyone tell me more about how people used to express the idea "not ... any( )time soon" or more specifically, "X is not going to happen any( )time soon"?