1. 有多种说法。比较委婉的说法是, be afraid to do sth. 例句:没受过训练的人因为怕出错而什么都不敢做。Those without training may be afraid to do anything for fear they would(will) do something wrong
根据不同语境,还有:
2. 他不敢做这件事,真是个
胆小鬼!He dare not do it! What a coward !
3. 我要做
失败者不敢做的事。I will do the work that a failure will not do .