Let people finish their sentences. The end is usually where the point lives.

Interrupting usually comes from enthusiasm rather than rudeness, which is why people do it without noticing. The cost is real, though, because most people build toward the thing they actually mean and it arrives at the end. Cut in early and you answer the setup instead of the point. You also teach them to keep the real version to themselves.

Hold your reply for one extra beat in every conversation today. Let their last few words land before yours start, and see what you have been missing.