不定式符号to的省略 ①.并列的不定式可省去后面的to. e.g. I told him to sit down and wait for a moment. ②.某些使役动词及感官动词(如see, watch, notice, hear, feel, look at和listen to等)后面作宾语补足的不定式一定要省去to.但在被动语态中须把to复原. e.g. ---- I saw the boy fall from the tree. ---- The boy was seen to fall from the tree. ③.介词but前若有动词do.后面的不定式不带to. e.g. The boy did nothing but play. 【查看更多】
