prescriptive grammar
noun
an approach to grammar that is concerned with establishing norms of correct and incorrect usage and formulating rules based on these norms to be followed by users of the language.
a set of grammatical rules based on such an approach.
Origin of prescriptive grammar
First recorded in 1930–35
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019