A daunting question about the usage of noun clauses and relative clauses (1)

A new member of Jose Carillo English Forum who goes by the username Kal recently asked me this daunting grammar question: “What are the types of noun clauses and relative clauses and what are their functions, forms, and usages?”

I say daunting because to answer it adequately will need an extensive review of two of the most complicated grammar forms in English. In fact, the forms and usage of noun clauses and relative clauses have been the most-often asked and most lengthily discussed over the seven years that I’ve been moderating the Forum. To answer Kal’s question, what I’ll be attempting therefore is a consolidation and distillation of those running discussions.