不定式结构作目的状语

不定式结构可以作状语，修饰动词、形容词、副词等，表示目的、原因、结果、条件等。

表示目的： They ran over to welcome the delegates. He bought a bicycle to go to town more quickly. He went home to see his mother. 注①：不定式结构表示目的时，通常句子的主语就是它的逻辑主语(参见以上三句)，但也有例外的情况，例如： I stopped for him to speak to me. He opened the door for the children to come in. He brought a porter to carry the boxes / bags. They sent a man to mend the window. He stood up to be seen better.