This is a more grammatically correct and polite way to phrase the request.
Here's why the original sentence was incorrect:
* "You be" is not grammatically correct. The correct form is "You are" or "You will be" depending on the context.
* "So kind as" is awkward and can be simplified to "please".
* "Correct grammar" should be "correct the grammar".
I hope this helps! Let me know if you have any other questions. 😊