prescriptivist

[pri-skrip-tuh-vist] /prɪˈskrɪp tə vɪst/
noun
1.
a writer, teacher, or supporter of prescriptive grammar.
adjective
2.
of, pertaining to, or based on prescriptive grammar.
Origin
1950-55; prescriptive + -ist
Related forms
prescriptivism, noun
British Dictionary definitions for prescriptivism

prescriptivism

/prɪˈskrɪptɪˌvɪzəm/
noun
1.
(ethics) the theory that moral utterances have no truth value but prescribe attitudes to others and express the conviction of the speaker Compare descriptivism, emotivism