YOU SAID:
"I haven't seen anything to confirm your boast yet,"
INTO JAPANESE
「あなたの自慢を裏付けるものはまだ何も見ていません」
BACK INTO ENGLISH
"I have yet to see anything to back up your boast."
INTO JAPANESE
「あなたの自慢を裏付けるものを私はまだ何も見ていません。」
BACK INTO ENGLISH
"I have yet to see anything to back up your boast."
Come on, you can do better than that.