it's a dream come true还是comes true

Question

it's a dream come true还是comes true为什么这里come true 不加s

Answer 1

为您解答
因为 "dream come true"是一个复合名词，意思是美梦成真。
比如
You are my dream come true.追答

如果come true是动词,这里是不可能用原形的，应该是
It's a dream that came,true.
It's a dream coming true.
才符合语法。

Answer 2

因为它是dream的定语