For all the diversity in human speech, as far as I know, every language has verbs and nouns.
No big surprise there: our world is full of things, like trees and lakes and ostriches and stars, something that nouns are very good at describing. And a lot of these things do things that we care about, like attack or fall or impede, which is where verbs come in.
But nouns refer to a lot of things that aren’t, well, things, like symmetry and justice and heaps and understanding. I can imagine an alien species in which every language uses different parts of speech for things and for collections of things that, as a whole, have a certain property. Call this an assemblage. Thus, to them, “rock” would be a noun, but “heap”, as in “a heap of rocks”, would be an assemblage. “Symmetry”, “pair”, and “order” would also be assemblages, rather than nouns.
They might even go further, and have yet another part of speech to describe the motion of things that has certain properties, like “dance” or “following”.
I want to emphasize that this wouldn’t change what the world is like; it would just change the words and sentences they use to describe it. And perhaps say something about the way they think.
To these aliens, a sentence like “time is money” would sound odd, because it would have a grammatical error (assuming that “time” is an assemblage, while “money” is a thing). In fact, we already have something like this in English, which treats nouns about people differently from nouns about things: “Who didn’t finish its dinner?” is bad English (note, too, how this makes the line “It rubs the lotion on its skin” in Silence of the Lambs particularly creepy).
It’s known that our brains are wired to treat people differently from other elements in our environment. See, for instance, the way we’re more prone to see people and faces in random noise like inkblots, clouds, and wood grain, than inanimate objects. So it seems reasonable to consider that our brains have special-purpose modules for nouns and verbs.
The obvious explanation is that our distant ancestors, before there was speech, still needed to deal with things and actions to survive. Once language appeared, the brain already had the infrastructure necessary to model things and actions, and manipulate that model, so evolution built on what was available. This can perhaps also be seen in the way that a lot of expressions treat abstractions as though they were things: “weighing the evidence”, “transferring ownership”, and so forth.
I don’t want to read too much into these sorts of things. I note, for instance, that in French, there’s a smaller distinction between nouns about people and nouns about non-people. And in German, the gender of both “Kind” (child) and “Mädchen” (young woman) is neuter.
Nonetheless, there does seem to be scientific literature on stroke patients who have trouble naming things, but no trouble naming actions, or vice-versa. And this suggests that the brain has separate modules for dealing with nouns and verbs.
In practice, I think this means that we are predisposed to see the world in terms of nouns and verbs, even when we’re not dealing with concrete things, and this can affect our perceptions. I guess it’s a bit like Neil DeGrasse Tyson explaining to people that a hot ball of rock, a huge ball of gas that generates its own heat, and an irregular lump of ice are vastly different things, and so it doesn’t make sense to lump Mercury, Jupiter, and Pluto all under the label of “planet”.
For instance, if we’re thinking about the way languages have migrated through history, it might be tempting to think of one language displacing another, much as putting a finger in a glass displaces water. But of course languages don’t behave the way that solid objects like fingers and water do; multiple languages can coexist, even in the same mind.
I guess what this all boils down to is that there’s a difference between what something is, and what it’s called.
Update, 15:47: Typo.