What's ergativity? In the field of linguistics, ergativity is a way for languages' syntactical systems (i.e. grammars) to organize themselves. It is one of several ways, and contrasts mostly with what might be termed accusativity. Which is to say, there are ergative features of syntactic systems, and accusative features. Most languages exhibit a strong leaning toward one system or the other, and to most Westerners, ergativity seems exotic because most European languages are markedly accusative. One popular counter-example is Basque, which is broadly ergative. But that's not exactly a widely-spoken European language.
Ergativity is very hard to explain to people without a lot of background in comparing the grammars of different languages and linguistic features, but here's an effort at an example, drawn from English.
English is mostly accusative. This means that the subjects of transitive and intransitive verbs are grammatically "the same," while the objects of transitive verbs are "different" from those subjects. In grammar, in English, subjects come "in front" and objects come "behind." For example:
The alligator dances the charleston.
The alligator dances.
The alligator, in both examples, is the subject, and, when the verb "dance" is intransitive (the second example), the subject, "The alligator" still shows up in front of the verb, showing it is a subject, not an object. We cannot give an intransitive verb "only" an object, e.g. neither of these below make sense (though for basically opposite reasons, one because of syntactic accusativity and one because of semantic accusativity):
*Dances the alligator.
*The charleston dances.
This is "normal" accusative behavior. But English does have some special verbs, which are "ergative" in terms of how they work. Consider this:
The alligator broke my pencil.
My pencil broke.
In this case, the "object" of the breaking in the intransitive usage of the verb "promotes" to the subject position, which is now not called the subject position but the ergative position, because in ergative systems, there's not a contrast between subject and object (nominative vs accusative) but rather a contrast between ergative and absolutive.
I'm sure this seems really strange and hard to understand. I didn't understand it at all in my intro to linguistics class, and didn't really figure it out until my second semester of syntax (for linguistic majors). Actually, it's possible I still don't really have it figured out.
Anyway, why am I thinking about this? I want to know, is Korean ergative?
I know Japanese is largely accusative. And I'm guessing that Chinese is what's called "split ergative," meaning it can't decide if it's ergative or not. But what's Korean? My current guess is that, like along so many other linguistic parameters, it's some kind of outlier… its "own damn thing." Korean strikes its own path through the linguistic wilderness. That's part of what draws me to the language.
But what path is that? Korean has noun case markers (just like, say, Finnish or Latin), but they are clitic (meaning they stand alone as word-particles, much as case markers do in Japanese). But, unlike anywhere else I've experienced, these case markers can be "stacked." Which is cool. You can attach a locative case marker to a noun phrase, and then attach a topic case marker to that. I saw one like that, earlier today.
In other words, you can make noun phrases play multiple syntactic roles in the sentence simultaneously. Which is cool. Worse, of course… all case marking of all sorts in Korean is entirely optional. You show case when you feel like it. Mostly, in higher registers and during careful speech, and in writing, of course. But… with all these case particles floating around like so much syntactic dust, are things ergative or accustive?
I'm going to investigate….
…그사이에 저는 떡볶이를 먹어요.
(=meanwhile+[DATIVE MARKER] I+[TOPIC MARKER] tteokbokki+[OBJECT MARKER] eat+[POLITENESS MARKER])