以下是一个简单的生日贺卡示例：

Dear [小朋友的名字],

Happy birthday! I hope you have a great day. I like you very much.

Love,

[你的名字]

如果是节日贺卡，你可以把“Happy birthday!”换成相应的节日祝福语，比如“Merry Christmas!”或者“Happy New Year!”。