Parents and caregivers can make a profound difference.
There are five factors that can influence how long it takes to learn a language, regardless of whether you study in a classroom or not.
The most important task in language learning, in my opinion, is the acquisition of vocabulary. If we have enough words, we can make sense of what we're reading or listening to and we can somehow express ourselves.
Subconscious language learning is a concept that leading language acquisition expert Stephen Krashen has demonstrated through extensive research, but is still challenged by many teachers. Though there is research to back up this theory that language is learned subconsciously, we are still not aware of how the language starts to stick in our brains.
I always spoke English with my parents and I never had any sense that my communication with them was in any way inhibited. There was no pressure to learn German or Czech. If anything, my parents wanted me to learn French, which we studied at school without any great success.
At the banquet of life, each language is another course. The better you can use languages, your own and others, the more you can enjoy the feast. At least that has been my experience. I have achieved varying degrees of fluency in 16 languages, and look forward to learning more. To me, there are three stages of language acquisition.
It's literally a beginner's mistake, but it can add months, if not years, to your eventual fluency of your new language.
In 1997 I went to the West Bank to study Arabic. Once there, I found that many of the students in the program were, like me, half Palestinian, and were there as part of an attempt to discover their roots. Before I left, I hadn't thought much about how language defines who we are, or what happens when the languages we use to build our identities are rendered useless.
The importance of a large vocabulary in your target language can't be overstated. Some are convinced we can converse quite comfortably with just a few hundred words. There are lots of articles on the topic. I don't agree.
One of the biggest myths I have come across though is that extroverts are the better language learners. I do not believe at all that you need to be an extrovert to learn a language. Language learning isn't about your personality type, rather it comes down to whether or not you possess the three keys.