Good morning interweb.
Let's worldbuild.
Morphosyntactic alignment has confused many conlangers,
so let's try to unpack it, starting with transitivity.
Verbs can either be transitive or intransitive.
Intransitive verbs, by definition, do not take objects.
"Blossom slept." Subject, verb. No object.
Transitive verbs, on the other hand,  require at least one object.
"Buttercup likes Bubbles." Subject, verb, object.
Now, S-V-O labels aren't all that useful here.
Instead, let's use these.
The subject of intransitive verbs is labeled S, for subject.
The subject of a transitive verb is labeled A, for agent,
AKA the one who actively does a thing.
And the object of a transitive verb is labeled P, for patient,
the one who passively experiences a thing.
S-A-P.
Now in the first sentence, it's unambiguous as to who is doing what.
Blossom is the sole participant, the one who both does the sleeping, and experiences the sleep.
Things are not so clear in the second sentence.
It could go either way, especially if we had free word order.
Buttercup could be the one who likes Bubbles,
or vice versa.
So we need some sort of marking to help distinguish between S, A, and P.
Marking everything would be kind of redundant,
and just highlighting S wouldn't help clear up the ambiguity,
so basically we have two options:
highlight A, or highlight P.
Now one of these systems should be immediately familiar to you.
If you don't see it, let's replace those nouns with pronouns, and hopefully, you'll see it now.
English, like most of the world's languages, is what's known as a nominative-accusative language.
Nominative-accusative languages highlight P by marking with the accusative case,
and group S and A together in the default, unmarked nominative case.
"She slept." "She likes her."
Nominative, accusative.
But about a quarter of the world's languages go the other option.
They highlight A by marking it with the ergative case,
and group S and P together in the default, unmarked absolutive case.
Unsurprisingly, we call these languages ergative-absolutive languages.
Think Georgian, the Mayan languages, and Basque, amongst others.
"She slept." "Her likes she."
Ergative, absolutive.
This is accusativity,
and this is ergativity.
And that was the first step in understanding morphosyntactic alignment.
Specifically, the "morpho-" part, which refers to the formation of words.
The "-syntactic" part refers to the structure of sentences.
Accusative syntax looks like this.
That is, the sentences are constructed such that like terms appear in the same part of the sentence structure.
Remember, accusativity treats S like A, and highlights P.
Same deal with ergative syntax, except ergativity treats S like P, and highlights A.
Note that these mean the same thing.
The agent does a thing, and the patient experiences it.
In both instances, Bowser is hitting Luigi.
The meaning hasn't changed, just the alignment.
We can also combine sentences using the "S is either like A or P" idea.
Take, "Luke arrived and Luke saw Yoda."
In accusative syntax, the second Luke can be eliminated without changing the meaning of the sentence.
"Luke arrived and saw Yoda,"
because S and A were the same.
This is called the S/A pivot, and accusative systems use it to build compound sentences.
If we had something like, "Luke arrived and Yoda saw Luke."
We couldn't eliminate anything because S and A are different.
Instead, we'd have to rearrange the sentence to make S and A the same;
that is, we use a thing called the passive voice.
"Luke arrived, and Luke was seen by Yoda."
Now we can use the S/A pivot to get rid of Luke without any problem.
"Luke arrived and was seen by Yoda."
Ergative syntax is just a mirror of this.
In "Ash arrived and Brock saw Ash,"
S and P are the same, so we can drop the last Ash by means of an S/P pivot.
"Ash arrived and Brock saw."
This may seem weird, but to a speaker of a language that uses ergative syntax,
these two statements mean the same thing and make perfect sense.
In "Ash arrived and Ash saw Brock,"
S and P are different, so we can't use the S/P pivot.
Instead, we have to use the antipassive voice,
which basically gets rid of P, and promotes A to S.
Which we can further collapse into, "Ash arrived and saw"-ish.
English isn't an ergative language, nor does it have an antipassive voice,
so this admittedly seems a bit like Voodoo witchcraft.
Links in doobly-doo to a wiki page on the antipassive voice.
Anyways, that was morphosyntactic alignment.
If the alignment shows up in the word level,
it's morphological.
If it shows up in the sentence level,
it's syntactical.
Either way, accusative systems treat S like A,
and highlight P.
Ergative systems treat S like P,
and highlight A.
At this point, you might think that in order to create an ergative language,
all you need to do is come up with some words, align, and mark them ergatively, right?
Well, sorta?
But it wouldn't be very naturalistic.
See, it turns out there's no such thing as a fully ergative language.
All ergative languages feature some degree of accusativity.
That is to say, all ergative languages are actually split-ergative languages.
There's a couple of ways split-ergative languages work.
The big one being the pronominal split, also known as the animacy split,
which follows this hierarchy: most to least animate.
Anything towards the right side of the spectrum is more likely to be ergative,
whereas anything towards the left is more likely to be accusative.
In Dyirbal, a language spoken in northeastern Australia, we see this.
First and second person pronouns are treated accusatively, and everything else ergatively.
But it's not always this neat.
Yidiny, again in northeastern Australia, does this.
Accusative on the left, and ergative on the right,
but in the middle, it's kind of a mix of both.
In effect, a tripartite system, where S, A, and P are all marked differently.
Think, "She slept." "Ze likes her."
FIY, direct marking is also something that might crop up here in a marginal way.
S, A, and P all receive the same marking or lack thereof.
"She slept." "She likes she."
You could also get this.
"She slept." "Her likes her."
Although, I'm pretty sure this alignment is purely hypothetical,
but it might be fun to mess with.
Anyways, then there's the split-S system.
Graphically, it looks like this.
To explain, let's look at "He cries" and "She speaks."
Crying is most often an involuntary act;
there's no volition on behalf of the crier.
In which case, semantically, "he" is an S argument that sorta has passive P-like qualities.
On the flip side, speaking is a deliberate act;
there is volition on the behalf of the speaker.
So "she" is a S argument with active A-like qualities.
Split-S languages lump all intransitive verbs that require volition into one group, Sᵃ,
and will mark the subjects of those verbs like A.
All the intransitive verbs that have a degree of non-volition to them,
go in a separate group, Sᵖ, and their subjects get marked like P.
In practice, this might look something like "Cries him" and "She speaks."
Fluid-S systems are similar, but have a slightly different approach.
They decide between accusativity and ergativity based on the meaning of a given verb in context,
which graphically looks like this.
In a fluid-S language, you might see things like "He cries" and "Cries him".
In the first phrase, S is marked like A, so there's volition.
He deliberately cries.
Whereas in the second phrase, S is marked like P,
so there's a lack of volition, i.e. he cries involuntarily.
Intresting side note, fluid-S languages can get away with way fewer verbs.
Verbs like slip and slide essentially mean the same thing,
but differ only in volition.
So if we control volition on the subject, we can do away with the duplicate verbs.
We can also create a tense-based split.
It's common for languages that feature this kind of split to have the past tense be ergative,
and all the non-past tenses be accusative.
The same semantic reasoning is going on here:
the past is very much out of our control,
so any statements we make are sorted by definition more in the passive P camp,
than in the A camp.
Whereas the present and future can be controlled somewhat,
so any action is likely to get more aligned with A.
Interestingly, there's another split going on here, as well.
"She slept." "Her liked she."
The morphology is ergative—the agent is marked—but the syntax is accusative.
S and A share the same slots in the sentence.
A morphosyntactic split, if you will.
Walmatjari, spoken in western Australia,
features such a split, as do many, many ergative languages.
And, let's do one more: the clausal split.
Here the split occurs between the main clause and subordinate clauses of a sentence.
In natlangs, we find examples of main clauses being treated ergatively,
and final clauses being treated accusatively.
Final clauses are relatively rare in English, but usually follow words like "that" or "lest."
"I make videos lest I be bored."
In a clausal split system, we might get ergative here, and accusative here.
We also see examples of main clauses being treated accusatively,
and relative clauses being treated ergatively.
Relative clauses in English tend to follow "who," "whom," or "which,"
or are those bits of a sentence between two commas.
"The man, who wears a brown fedora, is very tall."
Potentially accusative, potentially ergative.
And there is probably a whole bunch more of options out there,
but hopefully, I've given you some food for thought when it comes to morphosyntactic alignment.
It's an intense subject to get a hold of,
but the main thing you should take away from this video is accusativity, ergativity.
S like A, not P;
S like P, not A.
Good morning interweb, three things to talk about.
Point one.
"Ergativity" by R. M. W. Dixon is the canonical book if you are interested in this topic of ergativity.
I'll leave links in the doobly-doo.
It is long, it is expensive, the plot is non-existent, and there's hardly any pictures,
but it is so worth it. Check it out if you can.
For something more easy digested,
I'll leave a link to David Peterson's article on ergativity.
It's equally as good; much, much, much shorter.
Point two.
So throughout this video, I used S-A-P, subject-agent-patient.
Some systems use S-A-O, subject-agent-object.
Same deal, different nomenclature. Just so we're aware.
Point three.
A massive thanks goes out to everyone who made this possible.
The patrons, Isaac Silbert, Andrew Chehayl, Robin Hilton, World Anvil, and Ripta Pasay.
You guys are awesome.
And an extra thanks goes out to Sasha, who goes by the moniker /u/Adarain on Reddit.
They are a mod on the conlanging subreddit, which is an awesome subreddit.
You should be subscribed to it, links in the doobly-doo.
Anyways, without your help, this video would not have been very good,
so massive thanks to Sasha.
And that is that.
Thank you so much for watching, and until next time internet, Edgar out.
