Reddit mentions of Teaching by Principles: An Interactive Approach to Language Pedagogy (3rd Edition)

First of all, modern language teachers acknowledge that students don't all learn the same way. Some people would rather talk, some people would rather listen, some people would rather sit and memorize verb charts, and so forth. So when I say that modern language teachers have mostly abandoned the grammar-translation method, I don't mean that they've abandoned teaching grammar completely. Most would agree that some explicit grammar teaching is helpful.

We should be clear on what the "grammar-translation method" actually means, taking Greek for an example. A grammar-translation Greek textbook will explain to you (in English) that the aorist passive means such and such and functions in a certain way; it will give you a table of the aorist passive conjugation for you to memorize; and then it will give you Greek sentences to translate into English. If you're lucky, it will also give you English sentences to translate into Greek. This does nothing to help the student actually learn to use the foreign language. Greek and Latin are generally taught this way, and of course most Greek and Latin students would be mostly helpless in first-century Rome or fifth-century Athens.

This is the method that modern language teachers have abandoned. If you taught Italian this way, students would be able to explain Italian grammar to you in English and they would be able to translate Italian sentences into English. They would not be able to go to Italy and get a train ticket, a place to stay, or something to eat. It's much more effective to teach languages based on what students need to do, and allow that to determine what grammar and vocabulary you teach. So modern English as a Second Language textbooks, for example, often are organized by activity: going to the movies, going out to eat, going to the supermarket. They present grammar explicitly, but they present it meaningfully and in context.

Ultimately, learning a language's grammar (metalanguage, or language about language) does not equal learning the language, although it can be a means toward that end. The grammar-translation method teaches metalanguage rather than the language itself and does nothing to develop fluency and productive skill in the learner, which is why it's been abandoned as a method. But again, people still do teach grammar. We just tend to teach it meaningfully and in context rather than in isolation. And we've mostly abandoned translation as a measure of comprehension. Your ability in a language isn't measured in terms of how well you can construct a woodenly literal equivalent of the target language; it's measured in how well you can accomplish things in the target language.

For further reference, see grammar-translation in Wikipedia (too short, but decent). Brown's book has a good section on the history of language teaching.

As far as teaching methods and English second language acquisition H. Douglas Brown's Teaching by Principles: An Interactive Approach to Language Pedagogy is excellent. It has gotten great reviews in TESOL Quarterly and I have used it extensively.

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