役割を

role

→ 役割
phrase Uncommon #11,604
role 役割 means “role,” and を marks it as the object of the verb. It commonly appears in 役割を果たす, meaning “to play a role” or “to fulfill a role.”
JA: 彼女はチームで大切な役割を果たしています。
EN: She plays an important role on the team.

話す前に自分の役割をしっかり思い出せ

Before you speak, remember your role!

— ラスト、コーション (2007)

太陽エネルギー生活に大きな役割を果たすかもしれない

Solar energy may play a major role in our lives.

彼がそのテレビドラマ話す役割をした

He was the one who explained the plot of the TV drama.