英语中关于”grammar"的权威定义有哪些啊?我要英文版本的,

gram·mar n..
1.
a.The study of how words and their component parts combine to form sentences.
b.The study of structural relationships in language or in a language,sometimes including pronunciation,meaning,and linguistic history.
2.
a.The system of inflections,syntax,and word formation of a language.
b.The system of rules implicit in a language,viewed as a mechanism for generating all sentences possible in that language.
3.
a.A normative or prescriptive set of rules setting forth the current standard of usage for pedagogical or reference purposes.
b.Writing or speech judged with regard to such a set of rules.