開心的英文短句如下：
1. I am happy.
2. I am delighted.
3. I couldn't be happier.
4. I am thrilled.
5. I am ecstatic about it.
6. I am having a good time.
7. I am enjoying myself.
8. I am grinning from ear to ear.
9. I am so excited and happy.
10. I feel blissful.
以上是一些常用的表達開心、快樂的英文短句，你可以根據自己的需要選擇使用。