We’ve all been there. You’re sitting in a meeting and someone comes out with the craziest idea, but for some reason they think it’s great. They think it will fix all your problems, whereas all you can see are the things they’ve overlooked, or the reasons why the idea won’t work.
Whether you’re in a meeting or discussing something by email, “that’s ridiculous” usually isn’t the best response to a bad idea.
Some English speakers try to get round the problem with vague language, hoping that people will read between the lines and understand that “that’s interesting,” “I’ll think about it,” or “I suppose we could try that” can all mean “no way, that will never work!” The problem is, especially when you’re working in a multi-national team, or when some people don’t express themselves clearly for fear of being impolite, you can end up with people thinking others love their ideas, when in reality the other colleagues have already dismissed them and moved on. I talked in more detail about this in my What English people say and what they really mean post.
“That would definitely make things quicker, but what would we do about …/I think there might be a problem with/have you thought about?”