I see. Thank you for your prompt comment. Just one clarification ... When you are saying "getting the basics down on something like Duolingo/Rosetta Stone", do you mean that "basics" here includes all levels (as far as I know, solid courses like Rosetta Stone or Fluenz - as opposed to Duolingo and similar apps - have multiple levels, where higher levels are pretty advanced) or you are talking about first 1-2 levels?

Duolinguo is a poor substitute for human interaction. It's a good tool to support other methods, but it encourages pattern matching rather than actual memorisation and there simply isn't enough variety in the examples to help you with translating unseen phrases. It's also not sufficient for speaking practice, but at least you can hear the text-to-speech.

There are some positives. The community is very active and helpful. They've done a lot better with the lessons. Japanese, for example, is much improved. It used to be that you'd get exercises in hiragana with no context at all.

I agree with the other post, you'll get much more out of a two hour class once a week than doing ten minutes of duolinguo a day. The claim that x hours is equivalent to a university semester is nonsense.

Your question was about optimality. It doesn't take much classroom time to get good - maybe two or three courses? (say 60 hours to A2/B1) That gets you enough of a baseline that you can start watching TV, reading papers. For example in our B1 lessons for Spanish, we'd actually read El País as an exercise.

Understood. I appreciate you sharing your insights. What course(s) did you use for Spanish? Any thoughts on Fluenz?

I ran through the Michel Thomas 8 hour audio course, then 3 semesters of evening class at my university (run by the language dept). That was about 60 hours of class time, 2 hours a week. By the end I would have been comfortable going for B1 with a bit of study. In terms of course level I finished up working on B2 level material. If I was doing it again I'd look at the Instituto Cervantes. I had access to grad student pricing, but even so it cost about 200 a semester.

At the time I was also dating a native speaker and we would watch Spanish TV with English subs as well as English TV with Spanish subs. I still have a lot of friends who are native Spanish speakers which helps.

No idea about Fluenz, sorry. One of my friends used Lingoda for German and seemed to have a decent time with it. They also do language marathons where you get a significant discount if you do daily lessons, but it's easy to miss one and then you don't get a refund.

Thank you so much for sharing very interesting and useful details. ¡Muchas gracias! :-)

I think the takeaway is that classes sometimes don't feel that useful at the time - I would often be doing homework the night before, or on the train, but it made a massive difference speaking to people regularly. The main benefit is it offers a structure that's difficult to get if you talk to strangers or even friends, or if you buy a textbook.

Professional (and experienced) teachers are careful to not use vocabulary that's beyond your level, but at the same time a good class will be taught solely in the target language. In that sense I would seriously look at Lingoda if you can't attend evening classes. You get structured lessons with real people with very flexible scheduling. I don't know what qualifications the teachers are required to have though, and it's important as a beginner that you have people who know how to teach (and aren't just regurgitating the material).

For Spanish, Instituto Cervantes (similarly for German you have the Goethe Institute) is the de facto international language school and you can mostly guarantee the teachers will be good.

Much appreciate your feedback, which is very helpful. I agree with you on balancing structural benefits of classes with vocabulary and other benefits of conversational practice with native speakers. I haven't heard of Lingoda before - will definitely check it out and keep it in mind.

So I went through the whole Duolingo tree for Portuguese and thought it was high quality and got me good a foundation. As others noted, there is no substitute for actual conversation/interaction with native speakers, and I wish I started that sooner. I also second the recommendation of using something like Anki or Quizlet for vocabulary practice. I only noted that it's good to have a base before starting with professional teachers because if you're budget isn't unlimited, you might not get the bang for your buck having teachers walk you through the most basic stuff like hello/how are you/how much does that cost/etc. that you can get with Duoloingo/Rosetta Stone or similar programs. But if you want to start off with Italki and lessons on day 1 with native speakers, it certainly won't hurt!

Got it. Very much appreciate your additional thoughtful insights.

Duolingo works very well as an introduction so you can get a taste of a language.

There's no point doing higher levels on duolingo - if you actually want to learn a language to conversational level and beyond then proceed directly to memorising vocabulary with spaced repetition software such as Anki. It is much more effective.

The person who might benefit from higher levels on duolingo is the traveller who does not aim for conversational level but wants to pick up enough words to get by.

I see. Thank you for sharing your thoughts.