有个英语翻译不太明白

anxious to see if his fellow actor had at last learnt his lines此处可以被看作一个“词”，不用管它本身结构如何，它相当于一个形容词（并不是anxious引导的），修饰的是主语the gaoler。有人把它看作是主语的状语，有人看作是主语补足语。无论如何，名称并不重要，我们需要知道的是，the gaoler在“looked on eagerly”的同时，其状态是“anxious to see if his fellow actor had at last learnt his lines”。如果要改，只能理解为：The gaoler looked on eagerly, at the same time, the gaoler was anxious to see if his fellow actor had at last learnt his lines.当然，这样改了以后其语言效果是非常不同的。