“使坚定”常见的英文表达有 strengthen（one's resolve/determination）、fortify（one's resolve） 、steel（oneself/someone for sth.） 等，具体使用需结合语境：
strengthen（one's resolve/determination）：强调增强、巩固决心或信念，使其更加坚定。
例句：The support from his family strengthened his resolve to pursue his dream.（家人的支持使他追求梦想的决心更加坚定。）
fortify（one's resolve）：与“strengthen”意思相近，侧重于通过某种方式（如鼓励、经历等）使决心更加稳固、不可动摇。
例句：The difficult experiences he went through fortified his resolve to overcome any obstacles.（他所经历的艰难困苦使他的决心更加坚定，要克服一切障碍。）
steel（oneself/someone for sth.）：形象地表达“使（自己或他人）做好心理准备，坚定面对困难或挑战” ，有一种坚韧不拔、无所畏惧的意味。
例句：She steeled herself for the upcoming competition.（她为即将到来的比赛鼓足了勇气，坚定了决心。）