[Tainnor]

> 10 minutes a day, whether duolingo or not, will get you further then 70 minutes once a week in a crunch mode. That holds for language, playing musical instrument, sport, whatever. The hardest part in those is to keep interest and touch with activity over the long time it requires. And the big enemy are months when you pause the activity entirely.

My point is that you need both. Reviewing vocab etc. can be done as part of the "daily 10 minutes" (although it usually takes me longer). But learning about new grammar etc. usually takes longer than just 10 minutes. And once in a while you just have to sit down and read a more complicated text, looking up vocab, etc.

Again, it pretty much also depends on the language. For Japanese, I think it's impossible to get anywhere with just 10 minutes a day, I think.