昨天开心用英文怎么说

昨天开心用英语可以用 "I was happy yesterday" 来表示。这是一个常用的英语表达方式，用来描述过去的感受。

举例来说，你可以这样说：

"I had a great time yesterday. I was really happy." (昨天我玩得很开心。我真的很高兴。)

"I was in a good mood yesterday. Everything seemed to go my way." (昨天我心情很好。似乎一切都顺利。)

"Yesterday was a great day. I was so happy all day long." (昨天是个好日子。我整天都很开心。)

希望这些例句能帮助你理解这个表达方式的用法。