を驚かせた

surprised

→ を
phrase Uncommon #17,629
surprised Used to say that someone or something surprised someone. The を marks the person who was surprised, and 驚かせた is the past form of 驚かせる, “to surprise.”
JA: 彼女の突然の訪問は私を驚かせた。
EN: Her sudden visit surprised me.

突然物音老人を驚かせた

A sudden noise startled the old man.

その知らせはと同じくらいを驚かせた

The news surprised him just as much as it surprised me.

社長が殺されたという知らせは彼らを驚かせた

The news that the company president had been killed shocked them.

彼が引退を決意したことは私たちみんなを驚かせた

We were all surprised by his decision to retire.

留学しようという私の決心両親を驚かせた

My decision to study abroad surprised my parents.

私の功績王国を驚かせた

My accomplishments astonished the kingdom.

— HERO (2002)

以前は突然タンスから飛び出してを驚かせた最近はやってくれない

You used to suddenly jump out of the dresser and scare me, but you don't do it anymore.

— 恋する惑星 (1994)

彼の死は私たちみんなを驚かせた

His death shocked us all.