Axon wrote:What are some free online audio-based resources that can help me with polite "transactional" Korean? And, taking into account what you folks know about Korean, should I start by memorizing cafe phrases or start with general beginner materials?
I don't know necessarily about audio-based resources...
TTMIK is based on podcasts, but they talk a lot and take a long time to get to the point. When they do, it can be cursorily done. The PDFs are the most helpful. They have both romanization and Hangul the last time I looked. They have both free and paid content.
I liked Coursera's courses when I first started out. If Coursera is available in China, it might be a good resource to use. I understand since you asked for audio-based courses you may not want to learn to read Hangul, but it can be pretty easy. If this family lists their menu items in Hangul, it might impress them if you showed them your Hangul reading fluency -- even if it was just reading '카페라떼'. Coursera's courses cover Hangul and very basic shopping situations, like using numbers, a bit of bargaining, eating at a restaurant, and looking at clothes. Both courses are structured differently, and the 'second' (though really still basic and not any more advanced) assumes knowledge of Hangul. You can go through these courses at your own pace and I believe they're still free. They're both video-based, with quizzes interspersed throughout.
If Udemy is available in your country, there's a course another LLORG learner recommended upon a time called "Core Korean". If they're having one of their many sales, you can purchase all four courses in the series for $40-$50. The instructor is a native Korean and his English leaves something to be desired (as some of the translations of Korean sentences in the course seem to lack nuance), but the format of the course is very cool. This course is like an updated FSI/DLI that uses more relaxed drilling and less formal language. You don't have to know Hangul to use it, but it would be helpful. Since it's Udemy, the course is composed of a series of videos. The first course doesn't require you to really watch the screen while you work with it since the instructor goes through the concepts very deliberately in English and Korean, repeating often the important points. The teacher is very active on Udemy and answers any questions you may have. Though, of course, you might ask here and get an answer
That's all I can think of for now.