Prescriptive grammar

https://www.thoughtco.com/prescriptive-grammar-1691668

“According to linguists Ilse Depraetere and Chad Langford, “A prescriptive grammar is one that gives hard and fast rules about what is right (or grammatical) and what is wrong (or ungrammatical), often with advice about what not to say but with little explanation” (Advanced English Grammar: A Linguistic Approach, 2012).”