当表示方位的副词或介词短语位于句首时，主语是名词，谓语是不及物动词，句子会构成完全倒装。例如：

1. In front of the house sat a small boy.

2. Out rushed the dog when it heard its master’s voice.

3. In the middle of the room sat an old man.

4. Out of sadness comes the awakening.