How do I exit or cancel a bad bash command?

I expect to get some flak for this, but I can't find the answer anywhere. It seems like it should be so obvious. Sometimes, when I type a bad command in a bash terminal, the cursor just jumps down to the next line without any error or anything. I can't tell what I did wrong. It's like I'm stuck in the program. Reenactment: $ tidy Me: "Oops! That's not what I meant to type..." :q Me: "That didn't work..." :exit :quit exit quit /exit /quit -exit -quit -wtf??? I know I screwed up but how do I get back to the prompt without closing the terminal?