Gwynne's Grammar: The Ultimate Introduction to Grammar and the Writing of Good English (2014)
Part I. Gwynne’s Grammar
Chapter 1. This Is a Serious Business
Let no one be deceived into thinking that learning grammar is a luxury of relatively little importance, on the basis of such specious reasoning as that most people today manage to communicate adequately without having ever studied it formally. Learning even one’s own language without systematically learning its grammar is far slower and less efficient than otherwise. And anyway, even the most intelligent people seldom do get a completely accurate grasp of English from a grammarless education and can all too easily make elementary mistakes—such as “Between you and I” and the politically correct illiteracy “Anyone in doubt should ask their teacher”—that would never have been made at any level of society fifty or sixty years ago.
It is as well to emphasise that effortless knowledge of these elementary basics of grammar is indispensable for accurate English, Latin and Greek, and any other European language. In what follows, at least the definitions in bold print should be learnt exactly by heart, including even their word order. All the other definitions and explanations should at least be thoroughly understood, and learners should be able easily to think up sentences of their own that give examples of any of the defined terms.
The other use of bold print is to indicate the first time any important term is used in any discussion of it to make it easier to find it whenever you need to.