をこわした

broke

→ を
phrase Rare #40,272
broke Used when someone broke or damaged something. The を marks the thing that was broken, and こわした is the past form of こわす.
JA: 妹が私のカメラをこわした。
EN: My younger sister broke my camera.

君はわざとをこわしたのかそれとも偶然に

Did you break the window on purpose, or was it an accident?

ジョンきのうをこわした

John broke the window yesterday.

トム窓ガラスをこわした

Tom broke the windowpane.