Without a doubt the younger you are the easier it is to learn a foreign language. To such an extent that it is recommended to read or talk to your infant in another language to get he or she accustomed to the sounds of the target language and other languages in general. The easiest way to become bilingual (or multilingual) is to become so from birth. However, for those of us that don't have bilingual parents, or never got a chance to learn another language early on, there's still hope. It's true that the longer you wait the less likely you are to reach native speaker pronunciation. But, with hard work and determination you can still become fluent in another language and even not completely sound like a foreigner. Some people, gifted with an ear for languages, can even reach near native pronunciation, even at much later stages in life. So, while you're better off the younger you start, you can always learn a language later in life if you are willing to put your mind to it.