Means no, not
[1]
 
Memory hook Resembles of the tail feathers of a bird does not mean 'tail feathers', it is only used here to help you visualize the parts of the character as they relate to the memory hook. disappearing into a cloud does not mean 'cloud', it is only used here to help you visualize the parts of the character as they relate to the memory hook. where you can not see it.
Grammar Note
The character negates the thing that follows it in the sentence. A special case of this is the pattern (verb) (verb) is often translated (verb) or not. When you build a sentence with (verb) (verb) do not add as the (verb) (verb) pattern already implies a question.
Combinatons
ChineseliterallyEnglish
不好not goodbad
Practice
ChineseliterallyEnglish
你好不好?you good not goodAre you ok (or not)?
马好不好?horse good not goodIs the horse good (or not)?
手好不好?hand good not goodIs (your) hand ok (or not)?
Dialog
ChineseliterallyEnglish
你好吗?you good (question)How are you?
我不好。你呢?I not good. you (question)I'm not well. What about you?
Next
 
[1] F-18-diamondback blast by Jarod Hodge from http://commons.wikimedia.org/wiki/File:F-18-diamondback_blast.jpg, rotated, under license: Public Domain in the United States