2.不定式的否定式

不定式的否定式是not/never(to)。

You have to be careful not to hit rocks，trees and other dangers．(人教大纲版高一上第17页)

你们必须小心以免撞到礁石、树木等危险的障碍物。

For drinking during a dinner，the best advice is never to drink too much．(人教

大纲版高一上第39页)

宴会上，饮酒最好不要过量。