Em-Dash

• Use spaces around em dashes for sentence breaks (e.g., the task — which is paramount — is to gather all information first). 

Use  em-dashes to indicate additional information that could be ambiguous if commas were used to offset it instead. This is especially pertinent when there are commas within text offset by the em-dash.

• Then I met and married my husband, who strangely enough — and I ascribe this to Providence — had been through the same process, had been in the same cult, and had experienced a dramatic conversion experience, and come to Christ.
• I was late for the first class and I remember wandering into this room at the top of — what was it — David Hume Tower I think, and being slightly confused because there was a man drawing a picture of a bucket on the blackboard, and talking about a container, uh, a container understanding of space.
• And it was a gorgeous experience, I really, I remember reading the book—and rereading, obviously, when you’re doing a review — and just having the sense that I was being given a glimpse into the lives of people who I hold in such enormous respect.

Use em-dashes to indicate that the speaker interrupts themselves.

• I remember saying out loud — I don’t know if it’s a prayer — but I was sitting in a cold flat with a miserable little fire in the grate, and I said out loud, “God if you exist, come out and show yourself.”
• I’m not very good with chapters and verses, but I know that there’s a, there’s a couple of verses, probably in Kings I think, or could be Samuel — I’m hopeless at these things — anyway, at the end of one chapter, we read, and the word of the Lord came to Samuel.** And then at the beginning of the next chapter we read, and the word of Samuel came to Israel.**
• And I believe that this way of studying, this way of doing theology, more easily brings us into — can I say — cognitive contact with the word.

Use em-dashes to indicate ideas that could be considered parenthetical additions in regular written text.

• And I think Eckart heard the same thing on one of his visits — my husband — I asked him at some point, you know, when you look back, are you feeling like you can relax a bit?
• I’m not one of these people who adulates Torrance, but I love how he’s changed my life because he above all — and J. B. [James B.] — have offered me Christ in ways that I can grasp, in ways that, you know, transform me.
• But I think most of all I would have wanted to start questioning why it could have been that then they could — all these young ministers — they could go out onto beaches, and into streets and church halls and village halls and do mission and today they couldn’t, they wouldn’t.
• So is there any aspect of the — what you know of your relationship with him — that might have been tacit and not clear to a stranger, if they were just to pick up that book.
• After Bob’s, um, classes at the universities stopped, we asked him — we being the group at the time — some of us asked him if we could continue.
• And throughout all that time Bob has faithfully sent this wonderful email — which needs to be on the website — every week. A distilled — I don’t know what to call it — summary of the passage, the topic we’re looking at, and then he leads us in worship.

Use a single em-dash to indicate a slight change in tone or subject.

• So the Study Service — that’s an unusual name.

Protip: Commas and em-dashes serve similar practical functions in text. Unless the text would be ambiguous if a different form of punctuation were used, rely on personal judgment calls for speech cadence to determine whether an em-dash is helpful.