YOU SAID:

On the way to the store, I was surprised by my sister.

INTO JAPANESE

店に行く途中、私の妹は驚かされました。

BACK INTO ENGLISH

On the way to the store, my sister was surprised.

INTO JAPANESE

店に行く途中、妹が驚いた。

BACK INTO ENGLISH

On the way to the store, my sister was surprised.