[Adverb Clauses]Showing Direct Contrast: While

Same meaning

Mary is rich, while John is poor.

John is poor, while Mary is rich.

While John is poor, Mary is rich.

While Mary is rich, John is poor.

The phone rang while I was studying.

連接詞跟分詞構句的用法

These sessions on Saturdays are aimed at improving the productivity of office workers while also providing positive encouragement.

He was busy thinking what to do next while pretending to watch television.