"Can an adult learn to speak a second language with the accent of a native? Not likely, but new research suggests that we would make better progress, and be understood more easily by our conversational partners, if we abandoned a perfect accent as our goal in the language learning process. Pronunciation can be learned—but it should be learned with the goal of communicating easily with others, not with achieving a textbook-perfect accent. Adult students of language should be guided by the 'intelligibility principle.'"
Via Doug Moore