“如果你是数的种子，你注定不会成为小草”用英语怎么翻译？

if you WERE a seed of a tree, you would not grow into grass.

因为句子是虚拟的，所以要用were.
固定用法:
与现在事实相反：if + 动词过去式；would(第一人称可用should)+动词原形

If you are the seeds of the tree, you will not be doomed Xiaocaohu

安徒生有一句类似的话：
“It does not matter if you born in a duck-yard,as long as you come from a swan's egg.”

if you are a tree seed, you are destined not going to be grass