永不服输英文

应该是：Thanks to his strong personality and never admit defeat 吧！

就是never give up...跟永不放弃是一样的

because he is strong and never give up意思是：因为他很坚强，永不放弃楼主讲的语法不对~~外国人从来不这么讲，这么讲他们也听不懂。呵呵

never-say-die不屈不挠的unconquerable不可征服的invincible不可征服的unyielding不屈的unbeatable难以战胜的impregnable坚不可摧的resolute坚决的determined坚定的doughty强的courageous勇敢的strong强烈的spirited精神饱满的

he has firm faith and the spirit of never giving in