Listen to part of a lecture in a linguistics class.

The professor has been discussing Animal communication systems.

OK, so last time, we covered the dances honey bees do to indicate where food can be found and the calls and sounds of different types of birds.

Today, I'd like to look at some communication systems found in mammals, particularly in primates, such as orangutans, chimpanzees, gorillas... Yes, Thomas?

Excuse me, Professor. But when you talk about gorilla language, do you mean like, those experiments where humans taught them sign language or a language like...

OK, wait just a minute.

Now, who in this class heard me use the word "language"? No one I hope.

What we're talking about here, are systems of communication, all right?

Oh, sorry, communication, right.

But could you maybe, like, clarify with the differences?

Of course, that's a fair question.

OK, well, to start with, let's make it clear that language is a type of communication, not the other way around.

OK, so all communication systems, language included, have certain features in common.

For example, the signals used to communicate from the bee's dance movements, to the word and sentences found in human languages.

All these signals convey meaning.

And all communication systems serve a purpose, a pragmatic function of some sort.

Warning of danger perhaps or offering other needed information.

But there're several features peculiar to human language that have, for the most part, never been found in the communication system of any other species.

For one thing, learn ability.

Animals have instinctive communication systems.

When a dog, a puppy gets to certain age, it's able to bark.

It barks without having to learn how from other dogs, it just barks.

But much of human language has to be learned from other humans.

What else makes human language unique?

What makes it different from animal communication? Debber?

How about grammar? Like having verbs, nouns, adjectives?

OK, that's another feature. And it's a good example...

I mean I mention this cause like in my biology class last year, I kind of remember talking about a study on prairie dogs, where, I think the researchers claimed that the warning cries of prairie dogs constitute language, because they have this, different parts of speech.

You know, like nouns, to name the type of predator they spotted, adjectives to describe its size and shape, verbs..., but now it seems like...

All right, hold on a moment.

I'm familiar with the study you're talking about.

And for those of you who don't know, prairie dogs are not actually dogs.

They're type of rodent who burrow in the ground and the grasslands of the west United States and Mexico.

In this study, the researchers looked the high-pitched barks a prairie dog makes when it spots predator.

And from this they made some pretty... well, they made some claims about these calls qualifying as an actual language, with its own primitive grammar.

But actually, these warning calls are no different from those found among certain types of monkeys.

Well, let's not even get into the question whether concepts like noun and verb can be meaningfully applied to animal communication.

Another thing that distinguishes a real language is a property we call "discreteness".

In other words, messages are built up out of smaller parts, sentences out of words, words out of individual sounds, etc.

Now maybe you could say that the prairie dog's message is built from smaller parts, like say for example, our prairie dogs spot a predator, a big coyote approaching rapidly.

So the prairie dog makes a call that means "coyote", then one that means "large", and then another one to indicate "speed".

But you really suppose it makes any difference what order these calls come in?

No. But the discrete units that make up language can be put together in different ways.

Those smaller parts can be used to form an infinite number of messages, including messages that are completely novel, that have never been expressed before.

For example, we can differentiate between: "A large coyote moves fast." and say "Move the large coyote fast." or "Move fast, large coyote.", and I truly doubt whether anyone has ever uttered either of these sentences before.

Human language is productive and open-ended communication system, whereas no other communication system has this property.

And another feature of language that's not displayed by any form of animal communication is what we call "displacement".

That is, language is abstract enough that we can talk about things that aren't present here and now.

Things like "My friend Jo is not in the room." or "It will probably rain next Thursday."

Prairie dogs may be able to tell you about a hawk that's circling over head right now, but they never show any inclination to describe the one they saw last week.