Revised Differences for Fifth Printing

p.28

- When you are learning a "new language" that you can use without difficulty, it is largely composed of what you have already learned, and you are learning few new concepts. You think you've learned a lot efficiently, when in fact you haven't learned much new.

+ When you are learning a "new language" effortlessly, that language consists mostly of "concepts you have already learned" and does not contain many "new concepts". You think you have learned a lot efficiently, but in fact you have not learned much that is new.

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