b)spoken used to emphasize that something is true 这是肯定的,毫无疑问〔用于强调某事真实〕
We’ll always need teachers, that’s for sure.
我们永远都需要教师,这是肯定的。
c)American EnglishAmE informal spoken used to agree with someone 当然,肯定〔用于表示同意〕
Examples from the Corpus
that’s for sure• He wasn't using drugs, that's for sure.• Because she was beautiful and couldn't do enough for me, that's for sure.• Certainly not in the Aero-Space industry, that's for sure.• He's the hardest man to get out, that's for sure.• International business man, that's for sure.• Sanders also ain't gonna like it, that's for sure.• They'd have to move to a smaller house, that's for sure.• It was not the breathing of a seventeen-year-old, that's for sure, but something more sonorous.