独立主格结构主要表示谓语动词发生的时间、原因、条件或伴随情况等，相当于一个状语从句或并列句。

1. 用作时间状语The work done (=After the work had been done), we went home. 工作完成后，我们就回家了。

2. 用作条件状语Weather permitting (=If weather permits), they will go on an outing to the beach tomorrow. 如果天气允许的话，他们将在明天组织一次海滨小游。

3. 用作原因状语An important lecture to be given tomorrow (=As an important lecture will be given tomorrow), the professor has to stay up late into the night. 因为明天要发表一个重要的演讲，教授不得不熬夜到很晚。

4. 用作伴随状语He was lying on the grass, his hands crossed under his head (=and his hands were crossed under his head).他躺在草地上，两手交叉枕在脑后。

表示补充说明一个猎人走了进来，他的脸冻得通红We redoubled our efforts, each man working like two. 我们加倍努力，一个人干两个人的活。注：独立主格结构表示时间、条件或原因时，相当于一个状语从句，一般放在句首，表示原因时还可放在句末;表伴随状况或补充说明时，相当于一个并列句，通常放于句末。