An interruption can help when missing information prevents you from following the rest. If someone explains a route using an unfamiliar building name, say, "Sorry to interrupt. Which building do you mean by the annex?" The purpose is immediately clear.
Keep the question narrow. A request for one location should not become a long story about the last time you visited. Once the answer is clear, say, "Thank you, please continue."
Judge whether the point can wait
If the detail is interesting but does not affect understanding, note it and ask later. If the speaker is about to make an important decision based on incorrect information, a timely correction may be appropriate: "Before we choose Friday, could I check one thing? The room is unavailable that day."
Conversation norms vary across groups and settings. In a structured meeting, use the agreed hand-raising or turn-taking method. In a casual discussion, a short pause and a clear opening may be enough.
Practice with a partner giving a thirty-second explanation. Interrupt once for a necessary clarification, then summarize the continuation. Ask whether your question helped or broke the thread unnecessarily. The aim is to participate responsibly: recover the information you need while preserving the other person's opportunity to finish their point and avoiding a competition for speaking time.