grammarian
/ˈɡræmərɪən/Definitions
1. noun
A person who is an expert in the structure and rules of a language, especially one who teaches or writes about them.
“The grammarian spent years studying the intricacies of ancient languages.”
2. noun
A person who studies the structure and rules of language, especially in relation to a particular period or region.
“The linguist was a renowned grammarian of medieval French.”