YOU SAID:

Hes quick on his feet but slow in his head

INTO JAPANESE

彼は彼の足に速いが、彼の頭の中で遅い

BACK INTO ENGLISH

He was fast on his feet, but slow in his head

INTO JAPANESE

彼は足が速かったが、頭の中は遅かった

BACK INTO ENGLISH

He was quick on his feet, but slow in his head.

INTO JAPANESE

彼は足が速かったが、頭の中では遅かった。

BACK INTO ENGLISH

He was quick on his feet, but slow in his head.