There are two different types of relative clause:
- A "defining"
or identifying clause, which tells us which person or thing we
are talking about.
- A "non-defining"
or non-essential clause, which gives us more information about the
person or thing we are talking about. This kind of clause could
often be information included in brackets (...)
Example:
The farmer (his name was Fred) sold us some potatoes. 
The farmer, whose name was Fred, sold us some potatoes.
It is important to see the difference between the two types of
clause, as it affects:
a. the choice of pronoun used to introduce the clause,
b. the punctuation - you must use commas with a non-defining
clause.
As the name suggests, these clauses give essential information to
define or identify the person or thing we are talking about.
Obviously, this is only necessary if there is more than one person or
thing involved.
Example:
Elephants who marry mice are very unusual.
In this sentence we understand that there are many elephants, but it
is clear that we are only talking the ones who marry mice.
Punctuation
Commas are not used in defining relative clauses.
Relative pronouns
The following relative pronouns are used in defining relative
clauses:
|
Person
|
Thing
|
Place
|
Time
|
Reason
|
Subject
|
who/that
|
which/that
|
|
|
|
Object
|
who/whom/that/ø
|
which/that/ø
|
where
|
when
|
why
|
Possessive
|
whose
|
whose
|
|
|
|
Notes:
1. The relative pronoun stands in place of a noun.
This noun usually appears earlier in the sentence:
The woman
|
who/that
|
spoke at the meeting
|
was very knowledgeable.
|
Noun, subject of
main clause
|
relative pronoun referring to 'the
woman', subject of 'spoke'
|
verb + rest of relative clause
|
verb + rest of main clause
|
2. Who, whom and which can be replaced by that.
This is very common in spoken English.
3. The relative pronoun can be omitted (ø)
when it is the object of the clause:
The mouse that the elephant loved
was very beautiful.
OR The mouse the elephant loved
was very beautiful.
Both of these sentences are correct, though the second one is more
common in spoken English.
The mouse
|
that/ø
|
the elephant loved
|
was very beautiful.
|
Noun, subject of main clause
|
relative pronoun, referring to 'the
mouse, object of 'loved'
|
verb + rest of relative clause
|
verb + rest of main clause.
|
(You can usually decide whether a relative pronoun is an object
because it is normally followed by another subject + verb.)
4. Whose is used for things as well as for people.
Examples:
The man whose car was stolen.
A tree whose leaves have fallen.
5. Whom is very formal and is only used in written
English. You can use who/that, or omit the pronoun completely :
The doctor whom/who/that/ø I was
hoping to see wasn't on duty.
6. That normally follows words like something,
anything, everything, nothing, all, and superlatives.
Examples:
 | There's something that you should
know.
 | It was the best film that I've ever
seen. |
|
Examples:
 | A clown is someone who makes you
laugh.
 | An elephant is an animal that lives
in hot countries.
 | The plums that were in the fridge
were delicious. I have eaten them.
 | Where are the plums (that) I put in
the fridge?
 | Has anyone seen the book I was
reading?
 | Nothing that
anyone does can replace my lost bag.
 | Let's go to a country where the sun
always shines.
 | They live in the house whose
roof is full of holes. |
| | | | | | |
The information in these clauses is not essential. It tells us more
about someone or something, but it does not help us to identify them
or it.
Compare:
1. Elephants that love mice are very unusual. (This
tells us which elephants we are talking about).
2. Elephants, which are large and gray,
can sometimes be found in zoos. (This gives us some extra
information about elephants - we are talking about all elephants, not
just one type or group).
3. John's mother, who lives in
Scotland, has 6 grandchildren. (We know who
John's mother is, and he only has one. The important information is
the number of grandchildren, but the fact that she lives in Scotland
might be followed with the words "by the way" - it is
additional information).
Punctuation
Non-defining relative clauses are always separated from the rest
of the sentence by commas. The commas have a similar function to
brackets:
My friend John has just written a best-selling novel. (He went to
the same school as me) > My friend John, who
went to the same school as me, has just written a
best-selling novel.
Relative pronouns in non-defining clauses
|
Person
|
Thing
|
Place
|
Subject
|
who
|
which
|
|
Object
|
who/whom
|
which
|
where
|
Possessive
|
whose
|
|
|
Notes:
1. In non-defining clauses, you cannot
use "that" instead of who, whom or which.
2. You cannot leave out the relative
pronoun, even when it is the object of the verb in the relative
clause:
He gave me the letter, which was in a blue envelope.
He gave me the letter, which I read immediately
3. The preposition in these clauses
can go at the end of the clause, e.g. This is Stratford-on-Avon,
which you have all heard about.
This pattern is often used in spoken English, but in written or
formal English you can also put the preposition before the pronoun:
e.g. Stratford-on-Avon, about which many people have written is
Shakespeare's birthplace.
4. Non-defining clauses can be
introduced by expressions like all of, many of + relative
pronoun:
|
Person
|
Thing
|
all of
|
+ whom
|
+ which
|
any of
|
+ whom
|
+ which
|
(a) few of
|
+ whom
|
+ which
|
both of
|
+ whom
|
+ which
|
each of
|
+ whom
|
+ which
|
either of
|
+ whom
|
+ which
|
half of
|
+ whom
|
+ which
|
many of
|
+ whom
|
+ which
|
most of
|
+ whom
|
+ which
|
much of
|
+ whom
|
+ which
|
none of
|
+ whom
|
+ which
|
one of
|
+ whom
|
+ which
|
two of etc?
|
+ whom
|
+ which
|
Examples:
a. There were a lot of people at the party, many
of whom I had known for years.
b. He was carrying his belongings, many
of which were broken.
5. The relative pronoun which
at the beginning of a non-defining relative clause, can refer to all
the information contained in the previous part of the sentence, rather
than to just one word.
a. Chris did really well in his exams, which
was a big surprise. (= the fact that he did well in his
exams was a big surprise).
b. An elephant and a mouse fell in love, which
is most unusual. (= the fact that they fell in love is
unusual).
Examples:
a. My grandmother, who is dead now,
came from the North of England.
b. I spoke to Fred, who explained the problem.
c. The elephant looked at the tree, under which she had often
sat.
d. We stopped at the museum, which we had never been into.
e. She's studying math, which many people hate.
f. I've just met Susan, whose husband works in London.
g. He had thousands of books, most of which he had read.
WHERE TO PUT THE PREPOSITION IN A RELATIVE CLAUSE
There are often prepositions in relative clauses, and the relative
pronoun is the object of the preposition. This means that the
preposition can sometimes be omitted.
- The preposition is normally placed at the end of the relative
clause:
Is that the man (who) you arrived with?
Do you know the girl (that) John is talking to?
- In formal or written English, the preposition is often placed
before the relative pronoun, and in this case the pronoun cannot
be omitted:
The person with whom he is negotiating is the Chairman of a
large company.
It is a society to which many important people belong.
However, this is unusual in spoken English.
Examples:
 | The jungle the elephant lived in
was full of strange and unusual animals.
 | He was very fond of the mouse that
he lived with.
 | The tree under which they had their
home was the largest and oldest in the jungle.
 | In the middle of the jungle was a river that
all the animals went to every day.
 | It was the stream in which the
elephant and the mouse preferred to swim. |
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