YOU SAID:

the lantern was brighter than its wall

INTO JAPANESE

ランタンは壁よりも明るかった

BACK INTO ENGLISH

Lanterns were brighter than walls

INTO JAPANESE

ランタンは壁よりも明るく

BACK INTO ENGLISH

Lanterns are brighter than walls

INTO JAPANESE

ランタンは壁よりも明るい

BACK INTO ENGLISH

Lanterns are brighter than walls