“As children, we all have the instinct to acquire a set of rules and to apply them. Any toddler is already a grammatical genius. Without conscious effort, we combine words into sentences according to a particular structure, with subjects, objects, verbs, adjectives and so on. We know that a certain practice is a rule of grammar because it’s how we see and hear people use the language.”
http://www.wsj.com/articles/there-is-no-proper-english-1426258286?mod=e2fb