The man asks his son to study hard.改为否定句The man asks his son

The man asks his son not to study hard。 再问： 为什么不是填doesn't to study? 谢谢 再答： 如果用does not,可以是the man doesn't ask his son to study hard,但是不符合后面的3个空。 ask sb to do sth 是肯定句式， 否定的要说ask sb not to do sth。 为不定式的固定用法。 没有ask sb does not to do 的形式。