YOU SAID:
You are going to have perfected your English by the time you come back from the U.S.
INTO JAPANESE
あなたはアメリカから戻ってきた時間によって、あなたの英語を完成しているしようとしています
BACK INTO ENGLISH
By the time you came back from the United States, we are trying to have completed your English
INTO JAPANESE
あなたが米国から戻ってきた頃には、私たちはあなたの英語を完了しているしようとしています
BACK INTO ENGLISH
By the time you came back from the United States, we are trying to have completed your English
That didn't even make that much sense in English.