So glad it was timely (and clear)!

This is an interesting question. In this situation, you wouldn’t use an ellipse because nothing is technically being left out. The sentence indicates that Joan is explaining stuff that’s already happened; just because we don’t see a firsthand account, it doesn’t mean information has been left out. So here, you would just use a period.

Great questions!

Regarding ellipses at the ends of sentences: While some sources (including my beloved English Grammar for Dummies) say an ellipse at the end of a sentence should contain a 4th dot for the period, both the Chicago and AP Manual of Style say to leave it at 3 dots. So that’s what I go with.

Regarding starting with a hyphen to show continuing dialogue after an interruption: treat the person’s broken dialogue as one sentence, and don’t start the continuation with a capital letter.

“Please don’t—”
“Who do you think you are?”
“—speak to me that way,” John continued.

Please is capitalized because it’s the first word in John’s sentence. Speak is actually in the middle of his sentence, so it’s not capitalized.

I don’t know that I’ve seen ellipses used this way, but my guess is that it would be handled the same:

“Please…don’t…”
I waited, but nothing seemed to be forthcoming. “Yes?”
“…speak to me that way,” John continued.

Thanks for bringing these up, Hyacinthe. I can always count on you to raise good questions :).

I have a question about punctuation after an ellipsis at the end of a sentence. Should there also be a period, i.e., four dots? And what is your advice about beginning a sentence with an ellipsis or em dash to represent continuing with a broken thought or interruption? Is the first word capitalized?