At JSTOR Daily, linguist Chi Luu makes a case for emphasizing grammar rules that follow popular usage, rather than the pedantic standards set by centuries-dead classicists.
Here are the plain facts: many of these pop grammar rules… were magically pulled out of thin air by a handful of 18th and 19th century prescriptive grammarians…. Often these rules were modeled on an aspect of Latin, perceived to be a more ‘pure’ language than English, and went against actual historical and literary usage.