[ramblerman]

Krashen is brought up a lot as a "magic bullet". But I think there are 3 big caveats to his work that often don't get brought up.

- The amount of comprehensible input needed is really huge. So much so that someone who has 10-20 hours a week to learn a language might be better using an active approach.

- I used to think that if you understood a language certainly you would also be able to speak it. But this just isn't true. Passive vocabulary and active vocabulary (not to mention sentence construction) are separate and need to be practiced individually.

- In my own experience I have been very successfull with comprehensible input when paired with being in the country or studying the language during the day. This allows me to solidify links from what I've heard and read with the real world. AFAIK, his studies had a similar setup, always including students who were studying the language and then did extra reading/watching on top of that.

There is a bit of a pipe dream, that you will just watch mangas all day at your level and suddenly come out fluent.