Note - This is a discussion that broke out from the thread exit plan for isolated vocabulary. I don't see it as a practical solution as I still don't know what it means or how to do it. As far as I can see, "thinking in the language" means the same as "knowing the language" or even "having learnt the language" ie it is the intended end-state of the learning process. Telling someone that they have to "think in" the language to learn it is like telling them that the secret to getting rich is to make lots of money. Nobody? Well I would, for one. It's a meaningless sentence, because I find it difficult to imagine the when, where or why of saying it. Language is communication, and there is no useful message in a sentence like that.