以下是一些适合一年级学生写的英语贺卡祝福语：

"Happy Birthday! I hope you have a great day filled with fun and laughter."

"Happy Birthday, dear friend! I hope your special day is filled with lots of presents and cake!"

"On your special day, I want to say how much I like you. Happy Birthday!"

"Wishing you a very happy birthday. May your year be filled with happiness and joy."

"Dear [friend's name], I hope your birthday is as special as you are. Happy Birthday!"

"Happy Birthday! I hope your day is filled with lots of fun and games."