有读者问：
(1)I saw him going upstairs.
上面一句也可改为 I saw his going upstairs.吗？
不可。I saw his going upstairs.在语法上虽然没有错误，但习惯上没有人会这么说。这种常后接“代词宾格+-ing形式”结构的动词除see外，还有watch, notice, hear, have, want, hate, dread 等，实例如：
(2)He was watching it coming out of the burrow.
(3)I heard her singing .
(4)I won't have you smoking here.
(5)I hated him poking his nose in my concerns.
(6)We dread him returning to us.
当然这是指一般而言。有些动词，如 hate, 则有时也可后接“代词所有格+-ing形式”结构，实例如：
(7)Mother hates my cutting potatoes with a knife.
有的语法家说 imagine 一词也不宜后接“代词所有格+ -ing形式”结构，他认为下一句中的 your 应改作 you：
(8)I cannot imagine your loving such a girl.
但在不少情况下，imagine 之后用代词宾格或代词所有格则似乎都是可以的，如：
(9)Can you imagine them/their becoming more friendly with each other?
为什么上述动词常常后接“代词宾格+-ing形式”结构呢？其原因可能有二：一是由于-ing形式表示正在进行的动作，故是现在分词，如上述句（1）、（2）、（3）、（4）等；二是由于在人们的心目中，及物动词之后总是应该用一宾语，于是就将这里的代词宾格当作了宾语，而不用代词所有格了。
