At its roots, language is a means by which information is transmitted by humans to each other. Typically, its contours are determined by speech communities and linguists advocate the spoken form as language’s most important form; its most rich, varied, and dynamic form. While important to consider the differences between the spoken and written form, it should help to remember that sign languages are also completely robust, rule-governed, grammatical languages. American Sign Language in fact has a different grammar from English. So the central point to remember about language is that the main demand for it comes from a virtually universal need and desire to communicate.
In the past few decades, linguists have been forced to dig a little deeper into language in order to investigate just what differentiates human language, or natural language, from other forms of information transmission, both by artificial human means and by other organic means. Some bee species possess elaborate dances by instinct that allow them to communicate distance and identity. Parrots have been known to go beyond mere mimicry to some linguistic stimuli. Computers can perform extraordinarily difficult computations and hundreds of engineers work day by day to make them think more like us. Chimpanzees and other primates can learn and transmit arbitrary signals for tangible objects as well as actions. At the highest end of the spectrum of non-human language we have dolphins, Tursiops genus. I trust you already know that they are the dirtiest, filthiest joke tellers anywhere in the universe, but did you know that they are able to grasp simulations much faster than chimps, implying a much higher level of awareness?
Setting aside dolphins for a moment (dolphin linguistics are complex and far beyond the scope of this post), chimpanzees seem to perform some linguistic tasks relatively well. They can learn dozens of words. But we have learned that they possess only the most rudimentary of grammars. Words must be placed next to each other in a meaningless order, but usually repetitively next to each other. For example, “give food eat me eat food give….” (Still, some chimpanzees have been able to perform more impressive tasks as Emily Sue Savage-Rumbaugh showed in 1990.) Natural language is different. We are able to construct sentences that are virtually infinitely long, but that are not redundant. For example, “I learned that Annie bought the gun from Bob who said that Carolina borrowed money from David who…” could go on forever as a sentence. As a practical matter, this never happens. This is an important point as we will come to see later, but natural language has the property of recursion, which means that it can continue to spiral into its embedded phrases and dependent clauses forever. Don’t take recursion so seriously: the central point here is that humans can create infinite expressions from a finite set of discrete units of meaning (morphemes).
There have been a few attempts to demonstrate that the size of natural language is infinite, based on the fact that the grammar itself can spiral with new phrases forever and that the language can add words forever. Both properties, independently, would lead to such a conclusion. Based on the spectrum of translation outlined in my last post, I think we can look at natural language as the set of all human languages. Fundamentally, then, natural language is a flexible system, consisting of (many) sets of sometimes, but not always dynamic, rules for combining a functionally infinite set of words in order to convey information. The reason rules are sometimes dynamic is because, while many rules persist in language, they may occasionally do so out of inertia and therefore be broken when everyone in the speech community understands the expression despite its “illegal” form. One example of this is using the double negative in English. Although absolutely and utterly common in English of Chaucer’s day, the double negative fell from grace some time afterward. Still in use ever since, it is frowned upon by academicians, Strunk & White, and many other purveyors of proper English. This is why linguists frown upon prescriptivism. They do not dislike standardization, there are benefits to that. The problem is when people mistake standardization for right and wrong. Something may be standard, or it may be different, but it is not wrong, and likely is just as rule governed as the standard form. Witness the work of Walt Wolfram.
A language can add words in several ways, as shown partly by the translation spectrum. We can combine words from the language to mean something new, borrow words from another language, create new words out of thin air. This last one could be done simply by assembling sounds currently within language’s standard phonemic inventory for a new word. Typically, languages group various distinctive phonetic sounds into phonemes. For example, the ‘p’ in piranha is very different from the ‘p’ in stop. The first is said to be aspirated, which can be proven by placing your hand in front of your mouth when saying the word naturally. The second is unaspirated. In English, these sounds are grouped into the same phoneme /p/. In Hindi, they will lead to minimal pairs, where switching one for the other in a word creates different meanings. Therefore, they are in different phonemes. Switching them in English does not affect meaning. Let’s say a language has 30 phonemes. It would be a very long time before you run out of combinations of these sounds for making new words. And when you do run out of them for given word sizes, all you have to do is increase the word size. That gives you another virtual infinity of new word possibilities. And then you could add signs, as seen in the many sign languages of the world.
You could be thinking, “Well, aren’t there also infinite speech sounds? That is, phonetic sounds?” Yes. Just like the color spectrum, representing an infinite array of colors, there is an infinite array of sounds that our vocal chords can create — not to mention an infinite array of signs our hands can make. In the case of vocalizations however, like colors, they will be grouped in “best example” phonemes. The range of them may vary from language to language, but they will stick to a certain maximum deviation from the best example and always include the best example.
Remember that my definition of natural language here includes a grouping of all languages, which then implies that all phonemes are represented. Now let us add the phonemes have we have lost which may have existed in dead languages or simply been lost to current languages. We now have the entire array of speech sounds. By this method, all distinctive features should be represented. All these sounds can be brought into natural language, combined in every way morphologically and syntactically possible, and we wind up with an array of expressions that is boundless and infinite.
This is the scope of natural language. But there is more.