在状语从句的简化中，如果主从句的主语不一致时，该如何简化？

一般情况下要使用独立主格结构。
例如：1.Because mum was ill,I didn't go to school.----Mum being ill,I didn't go to school. 2.When he finished his homework,we went out to play.-----He finishing his homework,we went out to play.