YOU SAID:
I love to surf at the beach.
INTO JAPANESE
私はビーチでサーフィンするのが大好きです。
BACK INTO ENGLISH
I love to surf on the beach.
INTO JAPANESE
私はビーチでサーフィンをするのが大好きです。
BACK INTO ENGLISH
I love to surf on the beach.
That didn't even make that much sense in English.