hold on 是坚持住，握住不放的意思而hold out 是维持住，坚持要求和意见，不屈服的意思hold on当坚持They managed to hold on until help arrived.他们设法坚持住直到有救援到来.hold out 当坚持意见用Doctors hold out little hope of her recovering.医生帮助她康复的希望甚微。hold out 当维持用How long can we hold out against these attacks?我们对这些攻击能抵抗(维持)多久?
