Stackexchange.com is a fun Q&A site sheltering 156 different communities, each with its own topic. People post questions germane to the topic, and someone answers. It works a little like the more famous Quora, but the rules differ slightly. I belong to roughly a dozen topic communities, for some of which I enjoy writing, and others I just enjoy reading. Often, when I first sit down at the computer, especially if I'm still waking up, I might spend a little time on Stack Exchange as a warm-up exercise.
I am a once and future teacher of English as a Foreign Language, so a community of English Language Learners interests me. My students always surprised me with their questions, and most questions required some thought to answer because, as native speakers, we speak instinctively without thinking about it. Answering student questions requires some thought about language that native speakers are not accustomed to doing. Here, for example, is a question from the English Language Learners community: