给哥哥写英文贺卡，可以包含以下内容：

1.表达祝福和问候，例如：“Wishing you a happy birthday/Christmas/New Year, my dear brother. I hope this card finds you well and brings you joy. ”

2.表达感激和爱意，例如：“Thank you for always being there for me, my dear brother. I love you more than words can say. ”

3.回忆美好时光，例如：“Remember when we used to play games together? Those were the best times. I hope we can create more beautiful memories in the future. ”

4.鼓励和支持，例如：“I believe in you, my dear brother. You can achieve anything you set your mind to. Keep chasing your dreams and never give up. ”

贺卡的内容可以根据自己和哥哥的关系、具体的情境和想要表达的情感来自由发挥，最重要的是要真诚地表达自己的祝福和心意。