All humans are born with the ability and drive to learn language. Before we can even walk we start talking. From birth we are listening with intent, ready to learn our native tongue. Evolution has seen to it that we have an aptitude for language learning, but just how much of our abilities are we born with and how much to we acquire as we go along?
When we learn languages, we use the knowledge and skills acquired from the language we already know to understand this new language. That is, we take the rules of language, such as the use of verbs and adjective, sentence structure and syntax, and apply them to the new language. While these rules will always change and vary between languages there are some structures between languages that remain the same. This is known as universal grammar. Items than can be considered a part of universal grammar include tense, aspect and mood.
There are some rules that when applied to one language can be applied to practically any language. For instance, if a language has a name for the color red, it will have a word for the color purple. These rules do not always apply to every single language, which makes the theory of universal grammar difficult for linguists to prove. Universal Grammar forms part of the nature vs. nurture that has had scientists guessing for generations. Are we born destined to grow into a certain person with certain abilities, or do we acquire these characteristics along the way?
Within the field of linguistics there are two theories as to how we learn language as children. The theory of universal grammar was proposed by linguist Noam Chomsky. He believed that a set part of our brain was dedicated to language, and that this part of the brain had a set group of rules which we applied to language. It cannot be changed or altered, we do not learn it we are born with it. These structures appear in every language around the world. The alternative theory is that we are born with no pre-existing knowledge of language, rather it is something that we acquire.