I wrote this for another blog - essentially trying to introduce and work through some of the motivations for certain analyses of relative clauses without too much jargon…
My research focuses on the syntax of relative clauses. A typical relative clause is a type of subordinate sentence which modifies a noun. For example,
(1) a. the book that I’m reading
b. that blog post you’ve written
c. the man who saw me
d. a type of subordinate sentence which modifies a noun
The clause in bold is traditionally called the relative clause. They are theoretically interesting for a number of reasons. Some syntactic ones are: they are optional, i.e. nouns do not require a relative clause; the noun being modified seems to play a role in both the main clause and the relative clause; relative clauses resemble other constructions to a greater or lesser extent, e.g. interrogatives, possessives, etc.
The head of the relative
One of the major debates in the syntax of relative clauses lies in where we say the noun being modified originates in the syntactic structure (I will call this noun the relative head from now on). Consider the following example:
(2) You wrote the book that I’m reading.
Intuitively the relative head ‘book’ is the direct object of the main clause verb ‘write’. We also understand that ‘book’ is the direct object of the relative clause verb ‘read’. How can it be two things at once?
One option is to say that ‘book’ is base-generated, i.e. enters the syntactic structure, as the direct object of ‘write’ and is co-indexed with a relative pronoun in the relative clause (if two items are co-indexed, it basically means they refer to the same thing). This relative pronoun may be ‘who’, ‘which’ or silent (or ‘that’ depending on your analysis). Adopting the silent option and symbolising this silent pronoun as REL.PRO (for ‘relative pronoun’), the sentence in (2) would have the structure in (3) (the relative clause is placed in square brackets and the co-indexing is symbolised by the subscript ‘i’).
(3) You wrote the booki [REL.PROi that I’m reading]
But how does this capture the idea that ‘book’ is also the direct object of ‘read’? For this we say that the REL.PRO has moved from the direct object position of ‘read’ to the left edge of the relative clause. This gives the structure in (4).
(4) You wrote the booki [REL.PROi that I’m reading REL.PROi]
This captures our intuitions about how ‘book’ relates to the main clause and the relative clause. This is the sort of analysis found in Chomsky (1977) and Sauerland (2003), for example.
Another option would be to abandon co-indexing and say that ‘book’ is base-generated as the direct object of ‘read’. Instead of having a silent REL.PRO move to the left edge of the relative clause, the head of the relative itself moves (I use a subscript ‘1’ to symbolise that the two occurrences of ‘book’ are two copies of a single item rather than two independent items).
(5) You wrote the [book1 that I’m reading book1]
We would then say that the copy of ‘book’ in the direct object position of ‘read’ is not pronounced but is nonetheless present in the structure since we are able to interpret ‘book’ as being the direct object of ‘read’. The copy at the left edge of the relative clause is pronounced, giving the sentence in (2). This is the sort of analysis found in Kayne (1994).
The head, the ‘the’ and the relative clause
The type of relative clause we have been looking at is called a restrictive relative because it restricts the possible denotation of the noun. For example, (6) means that you wrote something and that something is a book AND that something is being read by me. In other words, the direct object of ‘write’ has to satisfy both the condition of being a book and being something that I’m reading. It allows you to distinguish this book from one that I’m not reading.
(6) You wrote the book that I’m reading.
To capture this, we say that the head of the relative and the relative clause are in the scope of the determiner ‘the’.
(7) [the [book that I’m reading]]
This can be capture in the syntactic structure by saying that [book that I’m reading] forms a constituent which excludes the determiner ‘the’. Now we have an interesting problem: ‘the’ appears with nouns, not clauses, which might suggest the following structure.
(8) [the [book [that I’m reading]]]
In this structure, ‘the’ requires a noun and so selects ‘book’. The relative clause modifies ‘book’ and so attaches to ‘book’. But there is evidence suggesting that the presence of ‘the’ is tied to the presence of the relative clause (a * means that the sentence is ungrammatical).
(9) a. London is beautiful.
b. *The London is beautiful.
c. The London that I remember is beautiful.
d. *London that I remember is beautiful.
A proper name, for example, ‘London’, cannot ordinarily appear with ‘the’ (hence the difference between (9a) and (9b)). However, when a proper name is modified by a relative clause, ‘the’ must appear (hence the difference between (9c) and (9d)). This suggests that ‘the’ requires the relative clause and not the noun! The following structure captures this idea (see Kayne, 1994).
(10) [the [[book] that I’m reading]]
Now, we have to come up with a way of relating ‘the’ to the head of the relative ‘book’, unless we want to abandon the idea that ‘the’ typically appears with nouns (an idea which might not be as crazy as it sounds). We could say that ‘the’ and ‘book’, by virtue of being close enough to each other in some non-technical sense, can enter into a relationship. Note that ‘book’ does not have a determiner of any kind. This is unusual in English.
(11) a. *I like book.
b. *Book is good.
We could therefore say that ‘book’ has an empty position for a determiner (I’ll call it D) that enters into a relationship with ‘the’ (see Bianchi, 2000).
(12) [the [[D book] that I’m reading]]
We can now make a prediction: if some other element occupies this D position, ‘the’ cannot form the required relationship and the sentence will be ungrammatical. A preposed genitive competes with ‘the’ in English, as seen in (13).
(13) a. the book
b. Bob’s book
c. *the Bob’s book
Now, if a preposed genitive occupies the D position that ‘the’ is aiming to form a relationship with, there will be trouble because ‘the’ and a preposed genitive cannot both be related to this same position, as seen in (13c). If ‘Bob’s’ is present, ‘the’ cannot be, but if ‘the’ is absent, the relative clause must be absent too. This accounts for why (14) is ungrammatical.
(14) *You wrote Bob’s book that I’m reading.
The only way to say what (14) intends to say is not to prepose the genitive, as in (15).
(15) You wrote the book of Bob’s that I’m reading.
Since ‘Bob’s’ no longer occupies D, ‘the’ is free to form a relationship with D and the sentence is grammatical.
That concludes this introduction to the syntax of relative clauses. We have seen that relative clauses are complex and have quite a counter-intuitive structure once we delve into the systematic patterns of grammaticality and ungrammaticality manifested in English. But that is the way of things – language is a part of the natural world and, just as theoretical physics is dumbfounding us with discoveries into the weird and wonderful nature of the physical universe, so too can theoretical linguistics make discoveries about the underlying structures of our linguistic universe (and all that without a Large Hadron Collider … for now).
Bianchi, V. (2000). The raising analysis of relative clauses: a reply to Borsley. Linguistic Inquiry, 31(1), 123–140.
Chomsky, N. (1977). On Wh-Movement. In P. Culicover, T. Wasow, & A. Akmajian (Eds.), Formal Syntax (pp. 71–132). New York: Academic Press.
Kayne, R. S. (1994). The Antisymmetry of Syntax. Cambridge, MA: MIT Press.
Sauerland, U. (2003). Unpronounced heads in relative clauses. In K. Schwabe & S. Winkler (Eds.), The Interfaces: Deriving and interpreting omitted structures (pp. 205–226). Amsterdam/Philadelphia: John Benjamins.