YOU SAID:
He sells sea shells by the sea shore.
INTO JAPANESE
彼は海岸で貝殻を売っています。
BACK INTO ENGLISH
He sells the seashells on the shore.
INTO JAPANESE
彼は海岸で貝殻を売っています。
BACK INTO ENGLISH
He sells shells on the coast.
INTO JAPANESE
彼は海岸に貝殻を売っている。
BACK INTO ENGLISH
He sells shells on the coast.
That didn't even make that much sense in English.