YOU SAID:

Your your English grammatically isn't correct for the reason being that you don't know English that well

INTO JAPANESE

あなたの英語が文法的に正しくないのは、あなたが英語をよく知らないからです

BACK INTO ENGLISH

Your English is grammatically incorrect because you don't know it very well.

INTO JAPANESE

あなたの英語はよくわからないので、文法的に間違っています。

BACK INTO ENGLISH

I don't understand your English well, so it's grammatically wrong.

INTO JAPANESE

あなたの英語がよくわからないので、文法的に間違っています。

BACK INTO ENGLISH

I don't understand your English very well, so it's grammatically wrong.

INTO JAPANESE

あなたの英語がよくわからないので、文法的に間違っています。

BACK INTO ENGLISH

I don't understand your English very well, so it's grammatically wrong.