The document discusses using the Lingua::EN::Inflexion module in Perl to easily inflect words based on number, part of speech, and other grammatical properties. It introduces the inflect() function, which can take a template containing tags like <N:error> and inflect the words correctly based on the number provided, such as producing the correct singular or plural form of nouns. Examples show how this allows generating grammatically correct error messages in a simple way compared to alternative approaches. It further demonstrates additional features like handling different numbers for one error and producing alternative wordings.