YOU SAID:

the boy did not eat bananas so his son ate grapes

INTO JAPANESE

少年はバナナを食べなかったので、息子はブドウを食べました

BACK INTO ENGLISH

The boy did not eat bananas, so his son ate grapes

INTO JAPANESE

少年はバナナを食べなかったので、息子はブドウを食べました

BACK INTO ENGLISH

The boy did not eat bananas, so his son ate grapes