Why is it important to know some history of the language?

[DIA]

Hello!
Could you tell me how some knowledge of the history of the English language will help the teacher explain things (for instance why do you say "give me the book" or "give the book to me" but not "give to me the book") to his/her students in an EFL class?

[Lucy]

Hello,

A knowledge of the history of language can help with vocabulary and pronunciation. It can be memorable for a student to hear the history of language items and anything that is memorable helps the learning process.

I am not so sure about the benefits of history and grammar. I am of the opinion that it is better to have a thorough knowledge of grammar and syntax.

Lucy