The article you read in the previous section was difficult because it entains many
center-embedded clauses. Consider, for example, the sentence "The cause experts the LSA sent investigate
remains elusive." We could paraphrase this sentence as: "The LSA sent experts. Those experts investigate a cause.
And that cause remains elusive." However, when the sentence is written as "The cause the experts the LSA sent
investigate remains elusive," it is extremely difficult to understand.
The important thing here is that these sentences are weird and hard to understand and look terrible,
but they're still grammatical. To see why these sentences are grammatical, how they are formed, and why they
are difficult to understand, we need to take a step back and think about some things about how English grammar works.
Read the discussion below. Once you have read and understood it, continue on to the practice/self-assessment questions
at the end of the page.
Relative clauses
Pretty much all languages have relative clauses. A relative clause is like a mini sentence
that you use inside another sentence, the same way you would use an adjective or other description. Consider these
English sentences:
I'm in a class with the smart girl.
I'm in a class with the girl from Brazil.
I'm in a class with the girl who won the award.
In each case, the underlined part is a modifier: it adds some extra description to modify "girl".
I didn't see just any girl; I'm in a class with the smart girl (not some other girl).
I didn't see just any girl; I'm in a class with the girl from Brazil (not some other
girl); etc.
The last example has the modifier "who won the award", which is a special kind of modifier: a
relative clause. Just like "smart" or "from Brazil", it adds some extra description to specify which girl I'm in a class with.
I didn't see just any girl; I'm in a class with the girl who won the award.
What makes a relative clause special, though, is that it's actually another sentence which was placed inside the main
sentence.
How do we create a sentence with a relative clause in English? Imagine we start with two separate sentences:
I'm in a class with the girl.
The girl won the award.
Now we need to combine these two sentences. We should try to come up with a rule to explain how this
works. Let's try to think of a step-by-step procedure, or "recipe", that we can follow to take these two sentences
and combine them into one. (I.e., let's try to describe our grammar relative clauses.)
Before we can describe our procedure, let's make up some terms to describe the important parts.
"I'm in a class with the girl" is the matrix sentence: eventually the main sentence will be about the fact that I'm in a class with
the girl. "The girl won the award" is going to be the embedded sentence: when we finish our procedure,
this won't be the main sentence anymore, it will instead be the mini-sentence that we put (embed) inside
the matrix sentence. And "the girl" is the head noun: it's the noun that we want our relative clause to
describe.
Now let's try to make our rule/procedure/recipe. A simplest first try at a procedure could be:
"Insert the embedded sentence into the matrix sentence, right after the head noun". Will that work?
If we follow that procedure, we will get the following sentence: "I'm in a class with the girl the girl won
the award." Clearly that is not correct. So we need to update our procedure a little bit.
Let's add another step to our procedure, to get the following procedure:
Find the phrase that is the same between the matrix sentence and the embedded sentence (i.e., the head noun).
In the embedded sentence, replace that phrase with that.
Next, insert the modified embedded sentence into the matrix sentence, right after the head noun.
Does this work? If we follow this procedure exactly, we will first change "The girl won the award"
into "The girl that won the award", and then we insert that into the matrix clause, so we get "I'm in a class with the girl
that won the award".
That's almost correct! The only difference is that the sentence we wanted to say "I'm in a class with the girl
who won the award", not "I'm in a class with the girl that won the award". We can modify our procedure a little
bit to fix that problem:
Find the phrase that is the same between the matrix sentence and the embedded sentence (i.e., the head noun).
In the embedded sentence, replace that phrase with that. (Or, if the head noun is a person, you can
use who instead of that.)
Next, insert the modified embedded sentence into the matrix sentence, right after the head noun.
Now we have a procedure that can take any two sentences and create a relative clause.
A complication
Let's think of a very similar sentence: "I'm in a class with the girl who I don't like". Can we figure out how
this sentence was created?
Let's assume that, just like the previous example, this started out by being two sentences:
I'm in a class with the girl.
I don't like the girl.
Now let's try to follow our procedure to turn these two sentences into one sentence with a relative
clause. "I'm in a class with the girl" is going to be the matrix sentence, "I don't like the girl" is going to be the
embedded sentence, and "the girl" is going to be the head noun. For the first step, we notice that
"the girl" is the phrase that's the same in both the matrix sentence and the embedded sentence. In the embedded
sentence, we replace "the girl" with who, to get "I don't like the girl who". Then we put this
sentence into the matrix sentence, right after the head noun, and we get: "I'm in a class with the girl I don't like who."
Obviously this isn't quite right. That means our procedure needs to be revised. It seems like we don't
just replace "the girl" with "who"; we have to always put "who" at the beginning of the embedded sentence!
For the first example we tried ("I'm in a class with the girl who won the award") our earlier, flawed rule just luckily worked,
because "the girl" was already at the beginning of the embedded sentence. But in the new example, "the girl" is not
at the embedded sentence. So we should change our procedure to something like the following:
Find the phrase that is the same between the matrix sentence and the embedded sentence (i.e., the head noun). In
the embedded sentence, replace that phrase with that. (Or, if the head noun is a person, you can use
who instead of that.)
Move that (or who) to the beginning of the embedded sentence.
Next, insert the modified embedded sentence into the matrix sentence, right after the head noun.
Now the procedure should properly create the correct sentence. You can try it on your own.
Subject vs. object relative clauses
The two examples we am in a class with illustrate an important difference between two kinds of relative clauses.
In the first example ("I'm in a class with the girl who won the award"), the head noun is at the beginning of the embedded sentence.
In the second example ("I'm in a class with the girl who I don't like"), the head noun is at the end of the embedded sentence. It's
easiest to see the difference if we leave a blank to remind us where the head noun originally was (before we
replaced it with "who" and moved "who" to the beginning of the embedded sentence):
I'm in a class with the girl who _____ won the award.
I'm in a class with the girl who I don't like _____.
A more accurate way we can explain this is: in "I'm in a class with the girl who won the award", "the girl" is the
subject of the embedded sentence ("The girl won the award"). In "I'm in a class with the girl who I don't like", "the
girl" is the object of the embedded sentence ("I don't like the girl"). Therefore, we call the first
kind of relative clause a subject relative clause. We call the second kind an object relative
clause. This distinction will be very important when we go on to further analyze why center-embedded sentences
(like "The cause experts the LSA sent investigate remains elusive") are difficult.
There's one more important difference between subject relative clauses and object relative clauses.
Let's see what happens if you don't put in the "who" or "that" (in linguistics we call this word the
complementizer or the relativizer) at the beginning of the relative clause. Here's how the subject
clause looks with and without the "who":
I'm in a class with the girl who won the award.
I'm in a class with the girl won the award.
Do these both sound good to you? Or does #2 sound worse? To me, #2 sounds pretty bad, at least in my
dialect of English. (If you've ever watched the old US sci-fi television series Firefly, you might notice that
the people in that show speak in a dialect that includes lots of sentences like #2 here, e.g. "I
ain't looking for help from on high; that's a long wait for a train [that] don't come." But in real American English
today, this sentence sounds unacceptable.) This shows that, in subject relative clauses, we need to include the
complementizer (who or that).
On the other hand, here's how the object relative clause looks with and without the "who":
I'm in a class with the girl who I don't like.
I'm in a class with the girl I don't like.
What do you think? To me, they both sound ok. In fact, the second one sounds maybe even a little better
(#1 sounds very formal). This demonstrates that, in object relative clauses in American English, we can choose not to
include the complementizer (who or that). An object relative clause without the who or
that is called a reduced relative clause (you can read more about it
here at Wikipedia).
With that background information, we are one step closer to understanding center-embedding and why it
is so difficult. But first, let's practice the concepts about relative clauses.
Think about relative clauses in another language (or another English dialect). Try to figure out a procedure/recipe for making relative
clauses in your language, just like we did for English here. (To start, it might be easy to directly translate
the sentences we used in this reading.)
Write your procedure here. Also provide an example subject relative clause sentence, and an example object relative
clause sentence. For each one, show how that sentence was created out of two other sentences, using your procedure.
(If you only speak English and relative clauses in your dialect work the same as what's described here, you can instead
try to brainstorm other complications to the recipe described here. Are there any other complications we haven't
addressed yet?)
Give me an example of an English sentence with a reduced relative clause.
![I ain't looking for help from on high; that's a long wait for a train [that] don't come.](https://i.pinimg.com/originals/47/f3/d0/47f3d0ccc825cd61d23b4a7064d14b30.jpg){kind=link}