Occasionally I write sentences containing subparts with extra information. I never know how to block off this information from the rest of the sentence. Three ways I have seen are dashes, commas, and ...
Does anyone use em dashes (or two hyphens) to denote speakers in dialogue passages? Joyce does this as does William Gaddis. Many others. I practice it, but my only "conceptual understanding" is that ...
I find it easier to write many things with parentheses, but I don't know if this is considered good practice. I would expect some might say that parentheses are indicative of excessive digression and ...