I agree with the article insofar as that learning a language solely via an app is not effective. However, I do not get the impression that the author actually has much experience learning languages through other means.

> The phrase “learning a language” is deceptively reductive. A language isn’t a
> singular monolith, but rather a complex interconnected system of components
> that build a way to communicate. The lexicon consists of the individual
> words, which speakers have to memorize. The syntax and grammar tell speakers
> how to properly structure those words in a sentence. Then there’s the writing
> system, which is the visual representation of words or sounds that allow
> words to be constructed (for example, in English, the writing system is the
> alphabet).

And, more importantly, there is also the task of learning the meaning of words in common idioms, as well as learning to recognize implicit meaning. Understanding syntax and individual words will never help you understand sentences like, for example, "sorry, I just had to get it out of my system". It will also not help you recognize the tone of a piece of writing.

> Duolingo often just drops a new particle on you without much explanation of
> what it does or even that it’s a particle at all. Memrise handles this a bit
> better, with lessons dedicated to how certain particles and grammar work, but
> it helps to have external lessons, an instructor, or best of all a native
> speaker to help explain some of the finer points of nuance in a language’s
> grammar.

It is debatable whether external lessons have an advantage over lessons in a mobile app, but that a native speaker is "best of all" suited to explaining the grammar of a language is a bold-faced lie. Native speakers do usually not understand grammar at all, because they have no reason to. (They do, however, almost universally across cultures often love giving an answer to grammar-related questions that you ask them, to avoid admitting to their lack of understanding.)

> You can learn as many words or sentences as you want, but until you’re able
> to have a conversation with another person, you’ll never be fluent. [...] For
> that reason alone, learning a language with an app should be a starting
> point, not the end. If you make it through an entire Duolingo skill tree or a
> Memrise lesson plan, it might be time to upgrade to an in-person class, or
> you might want to find a native speaker to practice with.

I think this more balanced assessment is the most important takeaway from the article. When learning any language, through any means, you will never progress beyond a basic level without practice. Practice does not necessarily have to entail having an in-person conversation, but you absolutely need to actually make use of the language skills you're acquiring: watch TV, write a blog, read a book, call someone, and so on.

Personally, I don't really recommend taking an in-person class if you already use an app and a textbook to learn. Sure, you can ask the instructor questions about particular grammar points that you encounter in your studies, but generally, if you're asking questions about grammar, you're doing language learning wrong. The human brain is much better suited to understanding and producing human language than it is to parsing text from a Backus-Naur form, so that's what you should focus on. A Japanese child doesn't understand the purpose of every particle either, but she easily beats you in fluency.

Related TED talk (good despite the sensationalist title): https://www.youtube.com/watch?v=d0yGdNEWdn0