What if I guess wrong the meaning of words or the grammar rules?

A common misunderstanding about learning a language through comprehensible input is that instead of being told what words mean and how the grammar works, we have to guess those things ourselves. But that’s not how it works. Using reasoning to guess the meaning of words and grammar rules is something that happens in the conscious part of our brain. But acquiring a language is a subconscious process. We don’t need to consciously understand the meaning of words or the rules of grammar to acquire them and be able to understand and produce them spontaneously. Rather, our brain uses the experiences we have with the language to build up a mental image. Instead of remembering each instance of each experience in which you heard a word, our brain is very good at summarizing those experience into patterns. It automatically figures out the elements in common between all the experiences in which you have heard those words. This process is even more pronounced with grammar, since grammar is even more abstract and difficult to explain. Even if you hear a new word and you happen to consciously think about its meaning and guess it wrong, it doesn’t mean that you are going to have problems with that word. A word is not completely learned in one single encounter, and when you encounter that word again in the future, the meaning that you guessed wrong won’t fit in the new context, so your memory of the meaning that you guessed wrong will not get reinforced; your brain won't build a pattern around it, and you’ll eventually forget that first guess. We also answer this question in our video FAQ (with English subtitles):