YOU SAID:

They had thought they were smart about it but in the end they weren't

INTO JAPANESE

彼らはそれについて賢いと思っていましたが、結局はそうではありませんでした

BACK INTO ENGLISH

They thought it was smart, but in the end it wasn't

INTO JAPANESE

彼らはそれが賢いと思ったが、結局はそうではなかった

BACK INTO ENGLISH

They thought it was smart, but in the end it wasn't