To understand what a language is, we need to define it. It’s actually not as easy as you think
A language is conditional relationship between two systems: coding substrate and information – which is used to store and transfer that information.
Since you understood nothing (just like myself), I am going to digest the definition piece by piece:
1. To store and transfer the information
This is both a part of the definition and the purpose of language. It’s no secret that a language is necessary to store, transfer and deliver the information. What kind of information is it then? Well, in case of natural languages, we are talking about coding and communicating thoughts, and, to some extent, any objects of reality. The most widespread and saturated languages such as English are literally capable to communicate about anything around us.
To encode the information, one needs some substrate, a “plate” or a “CD” to write on. It could be anything, but when we speak about natural languages, the substrate is usually either writing symbols or sounds produced by mouth. Mostly, we write or speak to convey information. There are other substrates: whistle, mimics, sighs, knots, beeping sounds – could be anything.
3. Association of the substrate and the information
An obvious step: to code the information with the substrate, we gotta link them to each other. Create an association. Or in other words, write some sort of a dictionary. Take a small portion of the substrate and connect it to a small portion of the information. Let “strawberry” be . And so on…
A small portion of substrate will be a combination of sounds or letters – words. As for the information (which is human’s thoughts, I remind) – the basic portion will be so called “object” of thinking. Object is something that one can think about – no way to it more precise. It could be some thing (a tomato, or a pencil), a situation (say, a competition, a fight), an action… Anything. Anything that can be thought of as a single whole.
4. Information and substrate – two systems
One cannot simply run and encode the information with the substrate. Think about it: a person can imagine infinite qty of colour shades or geometrical shapes. Similarly, he/she can produce an infinite amount of different sounds. To encode colour shades and shapes with sounds, each shape/shade is to be associated with certain sound/sound combination. Problem is: if you ever try to associate an infinite amount of whatever with another infinity, your brain will boil.
– /а/, 3% louder
– /а/, 7% louder
– /а/, 11% louder
– /а/, 18.992% louder
Also, there are heaps of intermediate colours between those listed. There also is another problem: if you say /а/ right now, you will never repeat in in your life. A super-precise voice recorder and sound analyzing software shows that people never pronounce two identical sounds. In other words, you won’t be able to say what you actually mean…
To make a language work, both substrate and information have to be prepared. We have to turn them into systems. Define a dozen of basic, representative colours; so that all other colours will be compared with them. Similarly, the multitude of sounds are to be systemized into phonemes: /а/, /i/, /o/ etc. Learn more about systematics here.
The word “red” in fact can correspond to billions of entirely different colours. While the /o/ sound can be pronounced in zillion different ways: louder, longer etc.
Because the info and the substrate are two systems, the most important property of a language is born – abstraction. We use a limited set of words to speak about what we think. However, the possible qty of thoughts is infinite. There are basic colours, such as red, yellow, green. But “red”, what exactly is it? Dark red, or purplish red? We could specify, say “It was dark red”? But how dark? We could go into more detail… but eventually we have to give up. Or, in other words, we have to abstract from irrelevant minute detail. Language is simply incapable to envelop even a single thought. You could try describing a single apple: it could take ten volumes, yet it won’t be complete…
4. Conditional association
One of the most important language characteristics that is often missed: the substrate and the information in any language are conditionally associated. In other words, some combination of letters/sounds encodes some thought not because they are “meant for each other”, but because there is a conditional association, an arrangement. “Dog” in its nature has nothing to do with domesticated carnivorous mammal. In some other language the same “dog” could be swearing. “Dog” has nothing intrinsically related to its meaning – people just decided that its gonna mean what it means.
Hence, painting is not a true language. Painters “encode” thoughts (or visuals, more precisely) using a substrate – paints and canvas. Yet there is no conditional association: to show a dog, we paint a dog, to tell that the sky is red, we fill it with red.
From conditional association, another language property arise: every language is interpreted. Dry language code is faceless and absurd. It “becomes flesh” only upon passing through listener’s/reader’s brain. In the brain, different words are connected to different objects of thought – sort-of a dictionary. Get a word – look it up in your head.
One final property to mention – all languages are regular. Separate elements of a language (words, sounds, morphemes, notions) are reproduceable. This allows for communication, actually: every language speaker knows the same words, the same rules, the same grammar. Every language is potentially limited. The same words and phrases are spoken/written all over again by different people.