I myself have recently been looking for resources to learn the rules of pluralization of regular nouns and have come across some very useful sources. One of them is the Promova blog, which explains the basics of grammar, in particular for plural nouns list by promova This resource provides accessible explanations and examples that are easy to understand. In addition, forums such as Reddit or specialized language platforms offer useful tips and discussions. There are also YouTube channels that explain grammar in an easy-to-understand way and give examples of real-world usage, which helps to reinforce the material.