动词不定式符号 to 在以下场合常被省略。 1. 在 see 、 hear 、 watch 、 notice 等感官动词和 have 、 make 、 let 等使役动词后面作宾语补足语的动词不定式要省略 to . 例如: We often hear her sing in the next room . What makes you think so ? 注:上述情况仅适用于主动语态,在被动语态中,作主语补足语的动词不定式不能省略 to . 例如: They were heard to sing the song . 2. 短语动词 look at 和 listen to . 例如: He often looks at other people play football . The children often listen to their teacher tell stories . 3. 在动词 help 后面作宾语或宾语补足语的动词不定式可以带 to ,也可以省略 to . 例如: Drinking more water can help you ( to ) get rid of your cold . 但是,如果主语不直接参加 help 后面的动词不定式所表示的动作,则动词不定式符号 to 不能省略。例如: The trip helped me to see much of the world . I think a walk will help you to eat more . 4. 当两个或两个以上的作用相同的动词不定式并列使用时,第一个动词不定式应带 to ,而第二个及以后的动词不定式可以省略 to .例如: I want to call on my teacher and ask him some questions . 注:当两个动词不定式为选择关系时,都不能省略 to .例如: I haven 抰 decided to go home or to stay at school this summer .