I promise you vs I warn you

[Volcano1985]

Does "I promise you" also mean "I warn you" ?

[Jamie (K)]

No, they mean something quite different.

"I promise" means, "I will do something for you."

"I warn you," means, "I am telling you that there will be trouble."

Why are you asking?

[Volcano1985]

Coz my dictionary says for the one of the meanings of promise something like this "I said, do or not, its up to you"

[Jamie (K)]

I have never known "I promise" to mean that. If that's what your dictionary says, I think it's wrong.

[Barb_D]

You can use "I promise you" as a sort of warning: Young lady, if you're in even one minute past your curfew, you'll regret it. I promise you that!"

But it's a specific use of "I promise you I will do something" (in this case, make her daughter's life miserable).