Irregular plurals ending with 'i' or 'ae' are not recognized in Humanizer

[clairernovotny]

Problem

Humanizer currently does not recognize certain irregular plurals, specifically words ending in "i" or "ae" (e.g., "cacti", "algae"), in places where pluralization logic should apply. This limitation is evident when comparing with Roslyn, which handles such cases using:

if (symbol.Name.EndsWith("i", StringComparison.OrdinalIgnoreCase) || symbol.Name.EndsWith("ae", StringComparison.OrdinalIgnoreCase))
{
    // Special handling for irregular plurals
}

As a result, users may encounter incorrect singularization/pluralization for these forms, leading to unexpected results in string conversions or linguistic displays.

Proposed Fix

• Update Humanizer's pluralization logic to recognize and properly handle words ending in "i" and "ae" as irregular plurals.
• Ensure these cases are covered in both singularization and pluralization methods.
• Add/modify tests in src/Humanizer.Tests to cover typical examples (e.g., "cactus" <-> "cacti", "alga" <-> "algae").
• Review existing resource files and registries to ensure these forms are localized correctly.

Impact

This change will improve Humanizer's linguistic accuracy and bring its behavior in line with best practices observed in other tools like Roslyn.

[ghostp13409]

Hi, I can look into it if it hasn't been solved already

[skdishansachin]

Hi! I noticed that the PR for handling words ending in “i” and “ae” was never merged. But in the latest version of Humanizer, "cacti".Singularize() and "alga".Pluralize() seem to work fine. Could someone explain if these are now handled by the existing irregular plural dictionary, and what the PR would have added on top of that?