We all use punctuation when we speak and think (why would we have all these different punctuation marks in writing otherwise?) I've noticed that people tend to speak about pauses when they speak about punctuation, particularly when they speak of periods and commas, but there is much more meaning in the different punctuation types than that.
Intonation, I think, is how we really 'tell' the different punctuations and thereby 'tell' what people mean when they speak. A question mark creates a sentence that rises in tone at the end. An exclamation, a rise in volume usually. I'm not sure how to describe what a colon sounds like, except that it invariably implies that something else is coming; in fact, that the most important part of the sentence is still to come.
A semicolon is like an addition. I can hear that it is different from a comma, not only because, sure, the pause is longer, but also because the intonation is different. Perhaps what the mark does is actually change the intonation of the second part of the sentence? (I'm just speculating here.) Seems to me that the first part of a sentence before a semicolon can sound like a complete sentence, but the part that comes after the semicolon sounds particularly like an addition, something closely related, but not necessary to the meaning of the first sentence. The words are rushed into, perhaps, but it's definitely more than that, too.
It's interesting to note, too, that unless we are reading and are surprised by a particular punctuation mark, the marks get incorporated into the sentences, at least the last word/s of each sentence. This is where the intonation that conveys the mark comes from. It is organically a part of the words of the sentence.
/Dea done trying to talk about something she knows nearly only by instinct.
