Today, more people learn English as a second language than any other in the world. The formation of modern English is paved by warfare and the fall-and-rise of ancient tribes and civilizations. This is the saga of a language that wouldn’t quit—responding to invasion after invasion by snagging the conquerors’ most useful words, streamlining their grammar, and turning their tongue into today’s linguistic superpower. The result is a language that has double the vocabulary of any other language. Today, more people learn English as a second language than any other.