他们都是感官动词
再问： 有哪些单词
再答： 感官动词有(see,watch,observe,look at, hear, listen to ,notice); 感官动词有一个重要用法：感官动词+宾语+do，在用作被动语态要补出to.例如:I heard her sing an English song just now. She was heard to sing an English song just now. 另外，使役动词包括(have,let,make)也有这种用法。如： I saw him go upstairs just now. He was seen to go upstairs just now
再答： thanks
