свою ручку

one’s own pen

→ свой
phrase Uncommon #20,461
one’s own pen Свою refers to something belonging to the subject of the sentence; its form agrees with ручку.
RU: Она забыла свою ручку дома.
EN: She left her own pen at home.

Джим уронил свою ручку и наклонился ее поднять.

Jim dropped his pen and bent down to pick it up.

Он вытащил свою ручку.

He pulled out his pen.

Он достал свою ручку.

He took out his pen.

Том поискал свою ручку.

Tom looked for his pen.