f it is the fluid capacity of it.

Understand "drink from [fluid container]" as drinking.

Instead of drinking a fluid container:
    if the noun is empty:
        say "There is no more [liquid of the noun] within." instead;
    otherwise:
        decrease the current volume of the noun by 0.2 fl oz;
        if the current volume of the noun is less than 0.0 fl oz, now the current volume of the noun is 0.0 fl oz;
        say "You take a sip of [the liquid of the noun][if the noun is empty], leaving [the nou