下次一定用英文怎么说

"下次一定"的英文表达为 "definitely next time"，来源是英语中的"definitely"和"next time"这两个词的组合。

例句：

"I'll definitely do it next time." (下次一定会做)
"I'll definitely see you next time." (下次一定会见到你)
"I'll definitely bring it next time." (下次一定会带上它)