YOU SAID:
she saw sea shells by the sea shore
INTO JAPANESE
彼女は海岸で海の貝殻を見た
BACK INTO ENGLISH
She saw the sea shells on the shore
INTO JAPANESE
彼女は海岸で海の貝殻を見た
BACK INTO ENGLISH
She saw the sea shells on the shore
That didn't even make that much sense in English.