When should I use “shall” versus “will”?

Shall is used for the future tense with the first-person pronouns I and We: I shall, we shall. Will is used with the first-person (again, I refer to traditional usage) only when we wish to express determination. The opposite is true for the second-person (you) and third-person (he, she, it, they) pronouns: Will is used in the future tense, and shall is used only when we wish to express determination or to emphasize certainty.

However,growing up as a native American speaker in Colorado, I never used "shall" in normal speech. However, I believe in questions it has become more common, e.g. Shall we go? but an American native speaker saying e.g. "I shall do that for you" will almost always sound affected or connote a Shakespearean context. I often have wondered in which parts of the world (England?) and which social echelons using "shall" in statements is actually still practiced by native speakers.