After that they should only be used for reference and nothing more. There are a lot of study materials out there (I recommend Benny Lewis’ Language Hacking courses, but there are tons). These courses are great for getting you from absolutely no ability in a language to being able to speak basic sentences and phrases within a few days’ time. They’re also good for teaching the most fundamental vocabulary (words such as: the, I, you, eat, want, thanks, etc.).

I’ve already mentioned Rosetta Stone which I’m not a fan of (you can get better bang for your buck elsewhere—read on and find out). Other than this, there is no shortage of language apps for you to take your pick: Babbel, Memrise, and Duolingo being the most popular ones. Each has its own shortcomings. None is a magic pill that gives you miraculous language abilities. But there is no doubt you can use them to complement your learning. If anything, the crowd-sourced sentences Duolingo uses to teach you grammar and vocabulary will provide great entertainment (and often a peek into what goes on in the minds of the people whose language you’re attempting to learn).

But remember, the greatest return on investment in language learning is forcing yourself to speak and communicate with others, and when you’re sitting in your bedroom with a book or a software program, you’re not being forced to formulate meaning and significance in the new language on the spot. Instead, you’re encouraged to parrot and copy concepts and patterns you’ve observed elsewhere in the materials. As mentioned before, I feel that these are two different types of learning and one is far more effective than the other.5