i (look at) a football in his bag

问题描述:

i (look at) a football in his bag
look at 为什么不能用see

look本身是不及物动词不可直接加宾语的,所以加at,
而see既可作为及物动词用,又可作为不及物动词用,
例:.I went to the hospital to see him.(及物动词)
2.To see is to believe.(不及物动词)