昨天天晴的英文怎么说

"It was a clear day yesterday" 或 "The sky was clear yesterday" 是表示昨天天气晴朗的常用表达方式。这两种表达方式都是由动词 "be" 和形容词 "clear" 组成的。

"Clear" 这个形容词来源于中古英语 "clær"，意思是 "bright, shining, translucent"。它通常用来形容天气、气象、天空、水、玻璃等东西。

例句：

The sky was clear and blue, and the sun was shining brightly. (天空晴朗，蓝色一片，太阳明媚。)
The water in the pool was crystal clear. (泳池里的水清澈见底。)
The window was so clean and clear that you could see everything outside. (窗户擦得很干净，很清澈，以至于你可以看到外面的一切。)