一辈子的翻译：for a lifetime/for life/entire life等；
半辈子的翻译：half a lifetime/half of a lifetime/half one's life等；
下半辈子的翻译：the rest of one's life/later part of lifetime等；
上半辈子的翻译：the first part of lifetime/the former part of lifetime等；
记你一辈子：I will remember you for a lifetime/I won't forget you for a lifetime.
记你半辈子：I will remember you for the rest of my life/I won't forget you for the rest of my life.
希望以上能够给您翻译您想要翻译的句子提供一些帮助，希望能够帮到您！
祝您生活愉快！
