If you don't know a second language, please don't learn one just for the sake of creating your own language, unless you are a genius like that guy Jared in The Pretender . But do learn one to enrich your mind, broaden your understanding of another culture, and to stave off dementia. I happen to speak pretty fluent Bulgarian and it has definitely helped me with Conlanging in a few ways. 'Pretty fluent' because i lived there for a couple years and spoke it well, but haven't had many opportunities since I've been back to speak it. Can't remember all the vocabulary words so well anymore. But being able to think in another language and knowing the grammer can free up your thinking as to what is possible for your conlang. It could be argued that knowing a language or two might also limit your vision as to what you will and won't attempt, but my experience has taught me that this is NOT a bad thing. When I was reading through conlang websites, I was bombar...
Making Your Own Language; Sharing Experiences, Resources, and Fun!