In El Congreso, a short story by Jorge Luis Borges, the lead character, Alejandro Ferri, sets out to find the perfect language for a secret society whose aim is to create a congress that represents all of humanity. This story is fascinating in many ways; for example, you might ask how a society can be both secret and represent all of humanity at the same time. But I was especially intrigued by the constructed languages that Ferri considers (but not ultimately accepts) as the universal language.
Anyone who's ever learned a second language knows the feeling that language is unnecessarily complex: irregular verb conjugations, cases (i.e. modifying a noun to indicate its role in a sentence), etc. Awful! So what could be more convenient than a rational language that has been designed with a limited and fixed set of rules? A language of reason, or Lingvo de kialo in Esperanto!
Esperanto and Voläpuk are two such languages, both created at the end of the 19th century. Voläpuk, which I'd never heard of before reading El Congreso, doesn't appear to have stood the test of time. But Esperanto is alive and well; it might not have become the universal language that it was designed to be, but it has a small following, its own Wikipedia with over 200,000 articles, and it is supported by Google Translate and Duolingo (a free platform for learning languages).
I've taken a few Esperanto lessons on Duolingo, and it's really easy to learn. The grammar is strictly regular, and has been stripped of all redundancy. For example, take the verb "to be", which conjugates as:
- Mi estas (I am)
- Ci estas (You are)
- Li/ ŝi/ ĝi estas (He/ she/ it is)
- Ni estas (We are)
- Ili estas (They are)
In other words, "to be" is not only regular, but it doesn't conjugate at all: estas is the only present tense of "to be", and personal pronouns ("I", "you", etc.) are used to indicate the doer; and the same principle goes for all other verbs.
This is quite special: Although I know only a few languages, I dare to guess that all non-constructed languages conjugate "to be" in a highly irregular way. But not so for Esperanto.
Because there is no conjugation, there is also no redundancy. The verb indicates when something is done: estas for the present, and estis for the past; and the personal pronoun indicates the doer. So you need both the verb and the personal pronoun to understand the meaning.
Again, this is special: Most languages have some half-baked redundancy in them. For example, "I am" is redundant, because if you read "am" you already know that "I" am the doer. (But "you are" is not redundant, because "are" works with "you", "we", and "they.")
The fact that Esperanto is regular and non-redundant makes it very easy to learn; but does it also make it a good language? Esperanto has been designed by a single person, the Polish opthalmologist Zamenhof, in a time when there was no psycholinguistic research on which he could base himself. So Zamenhof presumably based himself on a gut feeling of what a rational and beautiful language should look like. And—credit where credit is due—he did a decent job.
But say that we would design a new constructed language, using all psycholinguistic research that is now available, would it look similar to Esperanto? Or at least follow the same principles of regularity and non-redundancy? I doubt it, because both irregularity and redundancy, when used in moderation, serve a purpose.
Consider the big visual difference between "I am" and "he is". Because these two phrases are so different, having only the "i" in common, they are very easy to tell apart. Now consider the Esperanto counterpart: mi estas and li estas. These phrases differ only by a single letter, and are therefore more difficult to tell apart. For this reason, while I don't have the experiments to back this claim up, I'm confident that fluent English speakers take less time to understand phrases like "I am" than fluent Esperanto speakers take to understand phrases like "mi estas." In other words, an important function of irregularity is to make related phrases look very different, thus making them easy to tell apart.
The obvious downside of irregularity is that it leads to more phrases that must be learned by heart. Therefore, you shouldn't overdo it: Only common verbs should be irregular, as is actually the case in most languages. (The prime example being "to be", which is generally the most common and most irregular verb.)
A similar argument holds for redundancy. The phrase "I am" conveys the concept of "I" twice: first in "I", and then in "am" (because "am" must be combined with "I"). This is redundant, but it also speeds up comprehension. You can demonstrate the importance of redundancy easily in a simple experiment in which participants press a button whenever they see a circle on a screen. This is an easy task, and participants have no problem responding when a single circle appears on the screen; nevertheless, they respond more quickly when two circles appear on the screen: redundancy makes you faster, even in a simple circle-detection task, and probably also in language.
So irregularity and redundancy are useful tools, and the fact that Esperanto shuns them makes it a suboptimal language. Esperanto may be rational, but it is not a language for human beings, who are, after all, not rational.
But that doesn't mean that real languages make optimal use of irregularity and redundancy. In fact, they almost certainly don't. My gut feeling is that most languages are far more irregular and redundant than is optimal.
So, imagine that all psycholinguists came together, what kind of language would they design for Jorges' El Congreso? I don't know, but it's fascinating to think about.