Can you learn to speak (not to read or write) another language?
By reading books and audio books and internet
Definitely! I needed to learn to speak 3-4 languages over the past few years for my job, and in the process have landed on a pretty damn good method. It got me to C1 fluency in French in about 5 months, and I’m currently using it with Russian (and plan on reaching C1 equivalent fluency by September). At this point, I go in 4 stages:
* Stage 1: Learn the correct pronunciation of the language. Doing this does a few things – because I’m first and foremost learning how to hear that language’s sounds, my listening comprehension gets an immediate boost before I even start traditional language age learning. Once I start vocabulary training, I retain it better because I’m familiar with how words should sound and how they should be spelled. (Correct spellings in French, for example, are much easier to remember when there’s a connection between the spelling and the sound), and once I finally start speaking to native speakers, they don’t switch to English for me or dumb down their language, which is awesome sauce. If you’re learning a language with a different alphabet, this is where you learn the phonetic alphabet(s) (Kana, for Japanese or Pinyin for Chinese, for example)
* Stage 2: Vocabulary and grammar acquisition (itself in a few stages), no English allowed.
I start with a frequency list and mark off any words I can portray with pictures alone (basic nouns and verbs). I put those in an Anki deck(http://www.towerofbabelfish.com/Tower_of_Babelfish/Anki.html) and learn them. Once I have some words to play with, I start putting them together. I use Google translate (Exception to no English rule – just be careful there’s no English in your Anki deck) and a grammar book to start making sentences, then get everything double-checked at lang-8.com before putting them into my Anki deck. Turning them into fill-in-the-blank flashcards builds the initial grammar and connecting words. As vocab and grammar grow, I eventually move to monolingual dictionaries and writing my own definitions for more abstract words (again doublechecked at lang-8.com). This builds on itself; the more vocab and grammar you get, the more vocab and grammar concepts you can describe in the target language. Eventually you can cover all the words in a 2000 word frequency list as a foundation and add any specific vocab you need for your own interests.
* Stage 3: Listening, writing and reading work
Once I have a decent vocabulary and familiarity with grammar, I start writing essays, watching TV shows and reading books, and talking (mostly to myself) about the stuff I see and do. Every writing correction gets added to the Anki deck, which continues to build my vocab and grammar.
* Stage 4: Speech
At the point where I can more or less talk (haltingly, but without too many grammar or vocab holes) and write about most familiar things, I find some place to immerse in the language and speak all the time (literally. No English allowed or else you won’t learn the skill you’re trying to learn, which is adapting to holes in your grammar or vocabulary by going around them rapidly and automatically without having to think about it). I prefer Middlebury college, but a few weeks in the target country will work as well if you’re very vigorous with sticking to the target language and not switching to English. If you’re extremely strict with yourself, your brain adapts pretty quickly and learns how to put all the info you learned in stages 1-3 together quickly enough to turn into fluent speech.