Do This if You Understand But Can't Speak

I meet a lot of people who tell me, almost with pride, that they understand a language well but can't speak it. Usually two things are going on. Their comprehension isn't as broad as they believe, because they only follow the familiar topics they hear again and again. And they have made "I can't speak" part of their identity, so every meeting they sit through in silence confirms it. Which language do you understand far better than you speak?