Monologuists, fast families, video calls, being interrupted, ADHD and children
The rule holds everywhere. A few situations need a paragraph.
Real monologuists. Some people don't finish. Every apparent finish turns out to be a breath, and they can go for ten minutes. You don't have to be a captive, and there's a way to interrupt that isn't a jump. Wait for a finish, even a small one, a drop and a breath. Use their name. Ask a question about what they've just said. "Dave, can I ask, when you say the council wouldn't budge, what did they actually say?" That takes the turn at a finish, on their subject, and it's received as interest and not as seizure. If you need to change the subject, do it in the same shape. Name, finish, and then "can I take us back to the budget for a minute". Be honest, though, about how many of the people you jump on are this. Chapter 10's evidence is that most people stop within seconds when nobody jumps.
Fast families. At a table where everyone overlaps, the rule still applies to you, and it'll feel like you've gone quiet. You haven't. You're speaking at finishes, and there are finishes, even at that table. What you'll find is that your points land better because they're not competing, and that one or two of the quieter people at the table start getting to the end of things. That's not a small change for a family.
Video calls. Chapter 21 covered it. A full second, and mute.
Being the one interrupted. If you live or work with a jumper, the reading in chapter 8 is worth having. The jump reads as dominance and usually isn't meant as it. That doesn't make it pleasant. What helps is to stop, wait, and when they finish, say "I hadn't finished", pleasantly, and then finish. Most jumpers, told that once a day for a week, get the message without a conversation about it.
Hearing. If you jump because you genuinely can't tell when people have finished, especially in noisy places, and you find yourself asking people to repeat things, that's worth a hearing check. A GP can arrange one.
ADHD. The preface said it and I'll repeat it. The NHS lists being very talkative or interrupting conversations among the signs of ADHD in adults, alongside restlessness, being easily distracted, difficulty organising time and making quick decisions without thinking through the consequences. The symptoms usually start before the age of twelve. If that's a description of your whole life and not just of your dinner table, see a GP, who may refer you for an assessment. The method in this book still applies. It's just not the whole answer.
Children. If the interrupter in your house is a child, the rule for you is the same and matters more. Let them finish, every time, however long it takes. A child who's allowed to get to the end learns that the end is worth reaching. For teaching them not to jump, the hand-back is the model. "Hang on, your sister hadn't finished." Then let the sister finish. Then, "go on, what were you going to say?" They learn the shape by watching you run it.
Interrupting to help. Some jumps are rescues. The person is struggling for a word and you supply it. Once in a while, fine. As a habit, it teaches them that you'll do their sentences, and it's usually wrong, because the word they were reaching for wasn't yours. Leave the gap. They'll find it or they'll ask.