Forever, since I can recall, I've used a book for reference to English grammar, written by Peter Bullions, whenever I've felt ambiguous about whatever it be―from punctuation to syntax. And hitherto, I have been very assured by the laid-down rules provided by this seemingly extraordinary and concise book; although judging by the rules proposed by users on this website, it certainly seems as if the rules whereby I have been composing "grammatical" English texts all this time, and sharing my knowledge with others here, are no longer in use! So, I surely seem to be in a tricky predicament, where I find myself uneasy to impart conceivably-outdated information!
Do you suggest I abandon all which I've been taught by this book, or I alter the rules I reckon to be then-right but now-wrong, through meticulous comparisons for confirmation of validity?!
Please note that in this book, the 2nd person singular pronoun is thou, and the 2nd person plural ye. However, I have easily learned to ignore these evidently-outdated pronouns, and instead simply use "you" for both cases (which is ridiculously unclear, due to the confusion of whether a crowd or an individual is the audience).
Thanks for your recommendations.