Why do we "test" pupils on "rules" of English when English has no legal standards board? [closed]

Solution 1:

The goal is less the hard rules and standards and more the Practice of English as it is currently spoken. All here will admit that it is a moving target but then so is science and history. The tests given are only to affirm that the students have picked up the most recent lesson imparted to them and have not given up on the previous.

By way of English evolving unimpeded, it actually has, all this time. The rule used to be that there is Standard English and Non-Standard English. Plenty of non-standard people do just fine in their own way. Reliable communication on the other hand takes disparate people with common needs and provides them a currency of understandable speech. When usage eventually demands it then the language will unapologetically subsume the new usage and call it its own.