Short answers, pulled from the story.
Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning in spoken and signed forms, and it may also be conveyed through writing. The scientific study of language is called linguistics.
Stephen Anderson estimates the age of spoken languages at 60,000 to 100,000 years. Scholarly opinion on its earlier roots ranges from Homo habilis 2.3 million years ago to anatomically modern Homo sapiens. In March 2024, researchers reported that the beginnings of human language began about 1.6 million years ago.
Human language is open-ended and productive, combining a finite set of meaningless elements into an infinite number of meaningful units through a dual code. It is distinguished by recursivity, displacement, and modality independence. No animal has acquired the complex grammar known by an average four-year-old human, though a bonobo named Kanzi learned symbolic lexigrams.
Language is processed especially in Wernicke's area, in the posterior superior temporal gyrus of the dominant hemisphere, and Broca's area, in the posterior inferior frontal gyrus. A lesion to Wernicke's area causes receptive aphasia, and a lesion to Broca's area causes expressive aphasia. FOXP2 is the only gene definitely implicated in language production.
Children acquire whichever languages they receive sufficient exposure to in childhood, with no direct teaching required. Babbling begins around six months, words appear around 12 to 18 months, and an eighteen-month-old has a vocabulary of around 50 words. From roughly three to five years, a child's speech or sign comes to resemble adult language.
Academic consensus holds that between 50 percent and 90 percent of languages spoken at the start of the 21st century will probably have become extinct by the year 2100. Many small languages become endangered as their speakers shift to larger, more influential speech communities.