I'm currently teaching English online via video conference. I have no official teaching qualification (I cannot currently afford one), but I have studied languages to a high degree at university level and I have a growing number of regular students who are pleased with the lessons I offer.
Up until now, my lessons have mostly been conversation/vocabulary-based, but I would like to begin teaching grammar. Legal reasons aside, I do not simply wish to do this directly from a textbook to which I do not own the license. My question, then, is as follows:
Does anyone know of any TEFL grammar textbooks or courses that have a license that is free or cheap for individuals?
Beyond that, does anyone know of online TEFL courses or resources with a strong focus on grammar, or how adequately to prepare grammar classes for students?
Thank you very much in advance for all advice or suggestions.