不过你的两个句子都是可以的.只是所表达的意思不一样.
I saw his father beat him.see sb do sth 看见某人做了.这里的beat只能是动词原形.但是beat的过去式也是beat.
I saw his father beating him.see sb doing 看见某人正在做.
不过你的两个句子都是可以的.只是所表达的意思不一样.
I saw his father beat him.see sb do sth 看见某人做了.这里的beat只能是动词原形.但是beat的过去式也是beat.
I saw his father beating him.see sb doing 看见某人正在做.