The document discusses various approaches to language teaching that have been used, including grammar translation, audio-lingualism, cognitive-code learning, the direct method, the natural approach, total physical response, and suggestopedia. It analyzes the strengths and weaknesses of each approach based on principles of second language acquisition theory. Overall, it concludes that newer methods that provide more comprehensible input and focus on meaning over form tend to be more effective based on method comparison research and satisfy criteria derived from SLA theory better than older approaches like grammar translation and audio-lingualism.