How do you properly handle pluralization correctly across genuinely several different languages, given that different languages genuinely have meaningfully different specific grammatical rules regarding singular and plural forms?

Different languages genuinely have meaningfully different specific plural rules, for example English genuinely only has two distinct forms, singular and plural, while a language like Russian genuinely has several separate distinct plural forms depending on the exact specific number involved, and Flutter's ARB based localization system properly supports the standardized ICU plural message format, letting you correctly define genuinely separate distinct text variations for zero, one, few, many, and other cases as genuinely required by each individual specific particular language's own actual grammatical rules.

// app_en.arb
{
  "itemCount": "{count, plural, =0{No items} =1{One item} other{{count} items}}"
}