I don't quite get the difference between and relationship of vernacular Chinese to literary Chinese.
I know that "literary Chinese" does not represents sounds, the way an alphabet does, so it is difficult to use it for anything that must be spoken, like a play or a movie script. Therefore, there are "vernacular Chinese" variants that are deliberately designed to be spoken. My understanding is that the current version of "Mandarin", the standard Beijing language, is such a vernacular variant that was adopted early in the 20th century.
Does this mean that the "Mandarin" currently used is completely different from the Mandarin used during the Qing dynasty prior to 1900?
If so, does this mean that students essentially have to learn two different languages: the current vernacular plus the older Qing Mandarin?
What about older texts, like say the language of the Palace Encyclopedias of the 16th and 17th centuries? Were these basically the same as Qing Mandarin or a different language altogether?
Finally, how does "Classical Chinese" tie into this? Are the Palace Encyclopedias consider classical Chinese?