I've been wondering about the difference between questions that use can't you and can you not. Like: Can't you tell just by looking? [I read this from a comic-detective series] Can you not ...
"He is happy, isn't he?" If you did not use the contraction isn't he, in the question above, would the correct sentence be: "He is happy, is he not?" "He is happy, is not he?" Sentence #1 seems ...