persevere: implies an admirable determination and suggests both refusal to be discouraged, as by failure, doubts, or difficulties, and a steadfast pursuit of an end or undertaking: ~d doggedly in his efforts to get good grades.    （steadfast指坚定沿着某条道路implies a steady and unwavering course in love, allegiance, or conviction, 如steadfast in their support of democracy坚定支持民主）


persist: often suggests a disagreeable or annoying quality, for it stresses pertinacity more than courage or patience and is likely to imply self-willed opposition to advice, remonstrance, disapproval, or conscience: the infuriating teasing that ~ed despite all her attempts to stop it.     （pertinacious让人厌烦顽的坚持implies an annoying and irksome persistence，如a pertinacious salesman who wouldn't take no for an answer一个不罢休的销售，认为no就不是答案）  


persevere坚持毅力: 表示一种让人钦佩的决心，既拒绝被失败疑虑困难吓退，又坚定追求事业目标， persist坚持顽固(贬): 常表示让人厌烦不快的坚持，拒绝建议劝告反对意见，强调顽固而不是勇气耐心。


记忆方法: 1) 首字母2P想成二人同心其利断金<==更能坚持    出自<周易>利:锋利;断:砍断,折断。 比喻只要两个人一条心,就能发挥很大的力量。


         2）坚持的意思是面对困难或反对时仍然继续前进mean to continue in a course in the face of difficulty or opposition.