Translation of "Sonhara" in English

Uma vez Zhuangzi sonhou que era uma borboleta, mas quando acordou, ele não tinha certeza se era Zhuangzi que sonhara ser uma borboleta ou se era uma borboleta que agora sonhava ser Zhuangzi.

Once, Zhuangzi dreamed he was a butterfly, but when he woke up, he wasn't sure whether he was Zhuangzi who had dreamed being a butterfly or if he was a butterfly now dreaming he was Zhuangzi.