We recently posted two new grammar lesson articles that you may find interesting. The first is on homonyms, the definition of a homonym can sometimes vary, this article will help define what a homonym is, how to differentiate it from a homophone or a homograph.
The noun overview article has information on proper nouns, noun word forms, count nouns, non-count nouns, concrete nouns, abstract nouns, noun phrases, how to form singular or plural nouns, and common nouns.