Classical are refined Chinese used in official communication/literary record in imperial China/Korea/Japan. The grammar etc haven't really changed over 2 millenia, it is much like how Latin is to Italian/French/Spanish.
Historically, they are all obviously written in traditional Chinese characters, However, you can write it in Simplified Chinese since there's usually a 1-1 mapping between Simplified Chinese / Traditional Chinese characters.
Historically, they are all obviously written in traditional Chinese characters, However, you can write it in Simplified Chinese since there's usually a 1-1 mapping between Simplified Chinese / Traditional Chinese characters.