What do you know on sentence mining and how exactly does it differ from what we do on Duolingo?
Where would be the best place to try it for free?
Is it on Memrise?
This is related to this discussion for more information: https://www.duolingo.com/comment/22161915
Sentence mining is learning languages primarily from recognizing the way words are ordered in a sentence, then picking apart words and their functions within sentences, instead of learning individual words and trying to build sentences with them.
Memrise is good for repetition and memorization so I use it in conjunction with Duo, but they do focus on the one-word, two-word thing. They tend to start also with infinitives which in some languages isn't helpful (particularly in languages that do not conjugate their verbs). Duo tends to jump right in after the first lesson or two, and I love this! It's useful to see, up front, the usage of words within a sentence -- whereas on Memrise, they teach every individual component of phrases before you are familiar with the phrase itself. You can complete several Memrise language courses and be on Level 3 or 4 of a language and they're still teaching 2- and 3-word phrases. I feel like Duo covers more ground. But! Duo's audio and speakers just aren't good for some courses, and Memrise helps me remember things, which is exactly the basis of their method.
Busuu is excellent for speaking and writing and getting corrected by native speakers. The courses teach well, but their lessons are too easy. So again, I feel more challenged overall by Duo even if I'm more excited about Busuu due to the direct response of native speakers to your original sentences and audio.
It doesn't. Duolingo and Memrise are both already great at teaching you sentence structures and patterns intuitively. I would say Memrise has a bit better immersion, because they go around and record real people, but only their desktop website is free.
Of course exposing yourself to more listening and reading material in your target language can only be good. Like my English teacher used to say - first you need to look up almost every single word, then about half of them and soon you're not looking up at all anymore.
Apparently I do it sometimes without realizing it -- especially recently, since I want to re-golden my tree -- Duolingo isn't as repetitive as the guy in that video makes it out to be, but going through the lessons uses a lot of the same words, but I suppose it could work.
I haven't bothered much with other sites/programs as far as mining is concerned.