1. 主语(名词，代词，不定式，动名词，句子) 2. 谓语(动词或动词短语) 3. 宾语(名词，代词，不定式，动名词，句子。跟不定式作宾语的常见动词：want agree hope plan decide offer prefer wish intend fail desire refuse afford choose manage expect aim promise consent pretend neglect ignore omit happen determine demand threaten resolve decline propose undertake volunteer。