请问英语中“我明天休息”怎么讲？

I have a day off tomorrow.

I'll have rest tomorrow.

初中二年级有这样的句子，我们可以这样翻译I’ll have a day off tomorrow.

have a day off 是请一天假的意思
tomorrow is my rest day

I’ll have a day off tomorrow.

have a day off [简明英汉词典]
休假一天

tomorrow is my off day.