1. The understudy was substituted when the leading actor fell ill.

2. The understudy is substituted when the leading actor falls ill.

3. Hamlet was played by Romania's leading actor, Ion Caramitrou, to rapturous acclaim.

4. The man with a flower on his chest is the leading actor in tonight's soiree.

5. Baptists in America is a remarkable story of how one religious denomination was transformed from persecuted minority into a leading actor on the national stage, with profound implications for American society and culture.