to [fluid container]" as pouring it into. Understand "empty [fluid container] into [fluid container]" as pouring it into.

Understand "pour [something] in/into/on/onto [something]" as pouring it into. Understand "empty [something] into [something]" as pouring it into.

Pouring it into is an action applying to two things.

Check pouring it into:
    if the noun is not a fluid container, say "You can't pour [the noun]." instead;
    if the second noun is not a fluid container, say "You can't pour liquids into