说明
to-v 作形容词的补足语
核心问题
（1）“I’d be very happy to help.”
(2) One or two of them were surprised to see him.
上面的动词不定式 to help 和 to see him 应如何分析?
词典解答
我国出版的英语语法著作大都把上面的动词不定式分析为原因状语。CGEL则把它分析为形容词的补足语。从结构上说，它与表感情的形容词是密不可分的，因而它与那些修饰谓语动词的动词不定式是不同的。当然，从语义上说，这样的动词不定式有时具有“原因”的意味。下面是最常见的具有此种用法的形容词：
angry, ashamed, content, glad, happy, thankful, annoyed, astonished, bored, delighted, disappointed, frightened, interested, sorry, surprised, worried
He told the organizer that he had been surprised to receive an invitation to the conference but had decided to accept it. 他告诉大家的组织者，他收到大会的请柬感到很吃惊，不过他决定接受邀请。