>>10Sorry homes, you have reconstructed and classical languages mixed up. Ancient Greek isn't reconstructed. Ancient Greek was written down 2000 something years ago, while reconstructed languages have no written record, except in a few cases like Proto-Norse where we can say that there are gravestones and swords and whatnot with a few grammatically incomplete but nonetheless existent inscriptions. The most famous and the most useful reconstructed language is Proto-Indo-European, which is said to have been spoken before writing existed, therefore the entire thing is conjectural, and its grammar and lexicon have been revised a few times over the centuries.
Recon languages are not spoken for communication purposes, of course, their sole value is that they provide explanations for how daughter languages evolved and related languages diverged. But it's all just word games basically, probably the most complicated form of word game, as it's all made up and hypothetical but the rules are internally consistent and are able to make accurate predictions about modern languages.