What lies beneath the sentences that we say and hear? How do we know which words go together? Underneath our language is a layer of structure that defines the way that we understand everything - it tells us what words in the sentence go together, and what interpretations we're allowed. That's the syntax, and depending on how you hook words into the syntactic structures, you can end up very different places. Every language has a syntax, and the basics of how we build our syntax is a linguistic universal; in fact, it's part of Universal Grammar, the linguistic knowledge we all share.
To illustrate this, we talk about the basics of X' Theory, first proposed by Chomsky in the early 1970s. X' Theory gives you a template: X is a variable, and you can fill it with nouns (NP), verbs (VP), adjectives (AP), etc. Each word you introduce into the template gets a head, the most contentful bit in the phrase; a bar level, written X' and pronounced X-bar for whatever the part of speech is; and a phrasal level, so XP. So a noun would have NP, N', and then N. Then you take the templates and build syntactic trees out of them! The bar levels are repeatable and can give branches to either before or after the head, which allows us the flexibility we need to put together any kind of phrase, big or small. This lets us make sure that we can build any kind of sentence we might want to.
In the video, we talk about the need for syntactic structure, in terms of working back from a big heaping tossed-together bowl of word salad to a real sentence. If we didn't need structure, then we should be able to work back from the sentence in (1a) and get the meaning from the original sentence in (1b).
(1) a. A threatening hand is who Angel missing lawyer the is.
b. The lawyer who is missing a hand is threatening Angel.
But maybe you feel this is too crude an example. Having one that's just a total lack of structure just obviously makes it too hard to work back from. So we should maybe look at something else. Let's try this: make a simple, yes/no question for our sentence in (1b). We'd end up with the sentence given in (2).
(2) Is the lawyer who is missing a hand threatening Angel?
But… how do we know to move that is, and not the one between who and missing? I mean, how do we know not to make a question like the one in (3)?
(3) Is the lawyer who missing a hand is threatening Angel?
It can’t just be that we do it by saying, well, choose the second time is shows up; that rule wouldn’t cover a sentence like (4). You still need the last is to make a question there.
(4) The lawyer who is missing a hand and is covered in tattoos is threatening Angel.
But the rule can’t be choose the last is, either: that one would fail on a sentence like (5). Now you need the first is to make it a question.
(5) The lawyer is threatening the vampire who is running his own detective agency.
We can’t make a rule to capture all the different permutations of English that we know are right by just making reference to number or order. We need a rule that deals in structure instead. So first, let's draw a tree for the sentence in (1b), it'd look like (6). Note that is is serving as the head of its own phrase, TP, that rules the whole sentence. Since we don't particularly care about the who is missing a hand structure for this example, I'm just sticking a triangle there, but there's of course more structure inside!
So the rule that we'd need for making questions would be one that says you should take the is that's in the main clause, that main TP, and move it to the front of the sentence to make a question. You need to refer to that structure, since that other is inside the subject, the lawyer who is missing a hand, presumably has its own TP! But we can point at the main TP one, the one that goes with the main verb for the sentence, and come up with a rule that works all around.
We'll come back to moving things around and how that works with the X' structure in the future, but this should give a good idea of why structure is so important. This is just the first taste of syntax, but we'll fill in more with our next video! But if you can't wait, there's some good further explanations over at All Things Linguistic to try.
So how about it? What do you all think? Let us know below, and we’ll be happy to talk with you about syntactic trees, why we need structure, X' theory, or other approaches to capturing syntactic facts. There’s a lot of interesting stuff to say, and we want to hear what interests you!