不定式的否定形式由not或never加不定式构成。
We decided not to go out because of the bad weather.由于天气不好，我们决定不出去。
Never to have made any mistake is impossible.从不犯错是不可能的。
注意：谓语动词的否定和不定式的否定不同的意义
I did not promise to wake him up.我没有答应叫醒他。
I promised not to wake him up.我答应了不叫醒他。
