What is a clause?

A clause is a sentence within a sentence. Clauses are classified according to their functions in the sentence. They are:

Clause

A clause is a group of words containing a subject and a predicate. A sentence also contains a subject and a predicate. In this sense, a clause is a sentence. Actually, every simple sentence is a clause. The following two simple sentences are two clauses. 

  • Owls are nocturnal birds.
  • They sleep in the daytime.  

A sentence can contain two or more clauses. Look at the following sentence: 

  • As owls are nocturnal birds, they sleep in the daytime. 

Here, 'As owls are nocturnal birds' and 'they sleep in the daytime' are two clauses. 

What is a clause?

A clause is a sentence within a sentence. Let us see what the greatest grammars of the world say:

"A clause is a group of words that contains a finite verb." -Nesfield

"A clause is a group of words that includes a subject and a verb, and forms a sentence or part of a sentence." -Oxford Dictionary

"A clause is a part of a sentence which contains a subject and a verb, usually joined to the rest of the sentence by a conjunction." -Michael Swan

"A clause is a group of words that has both a subject and a predicate. It must have a verb that show tense. A clause can convey meaning on its own like a proper sentence, or it may be a part of a sentence." -Cambridge Grammar Gear 

Types of Clauses

There are mainly three types of clauses:

(i) Principal clause and

(ii) Sub-ordinate clause

(iii) Co-ordinate Clause 

Principal Clause

One clause of a complex sentence functions like an independent sentence. It is called the principal clause. Look at the following sentence carefully.

  • He is poor because he is lazy.

In the above sentence, 'He is poor' is the principal clause. 

Sub-ordinate Clause

A sub-ordinate clause is depended on the principal clause in the sentence. That is, a sub-ordinate clause functions as a part of the principal clause. It begins with a sub-ordinate conjunction. Sub-ordinate clauses are either noun, or adjective or adverb. Only a sub-ordinate clause itself cannot form a sentence. 

  • Owls are nocturnal birds which sleep in the day

In this sentence, ----"which sleep in the day" is dependent on the main clause. So, "which sleep in the day" is a sub-ordinate clause. 

More Examples of Principal & Subordinate clauses

In the following table, principal clauses are in the left column and sub-ordinate clause is in the right. Note that sub-ordinate clause begin with a sub-ordinate conjunction. 

Principal Clause
Subordinate Clause
I know
where he lives.
Tell me
what you want.
Everybody likes him
because he is honest.
You can learn more
if you read more.
Wait here
until I come back.

Types of Sub-ordinate Clauses

You have known that sub-ordinate clauses are either noun, or adjective or adverb. So, there are three types of Sub-ordinate clauses:

  • Noun Clause
  • Adjective Clause
  • Adverbial Clause 

Noun Clause

A clause which does the functions of a noun is a noun clause. That is, a noun clause functions as subject, object, complement, or appositive in the sentence. 

Noun Clause Conjunctions

Noun clauses generally begins with what, when, where, why, how, and that, although other variations are also possible.

Noun Clause as Subject of Verb

A noun clause can act as the subject of the verb. As a subject, noun clauses occur at the beginning of a sentence.

  • That he is very intelligent is known to me.
  • What you say is true. 
  • How Hamlet died was a mystery.

Noun Clause as Object of Verb

A noun clause can act as the object of the verb.  As object, noun clauses occur after the transitive finite verb of the principal clause.

  • I know where he lives
  • He asked me why I was late.
  • You cannot guess what type of person he is.

Noun Clause as Object of Preposition

A noun clause can act as the object of a preposition.  As object, noun clauses occur after the preposition.

  • I don’t believe in what you say
  • Everything depends on how they react
  • I know nothing except what you told me

Noun Clause as Appositive

A noun clause as an appositive occurs just after the noun it describes.

  • The news that he has died is not true. 
  • The report that he is sick is known to all. 
  • It is certain that he will come

Noun Clause as Subjective Complement

A noun clause as an subjective complement occurs after be verb.

  • The question is how he will respond.
  • This is what he said
  • Smartness is what a smart does

Noun Clause as Object Complement

A noun clause as objective complement occurs after the object of the main clause.

  • You can call me whatever you like
  • The country will elect their king whoever defeats the Sphinx

Adjective Clause

An adjective is a word that modifies a noun or pronoun. Sometimes clauses can modify nouns or pronouns. We call them adjective clause. Read the following two sentences:

  • The clever boy got a scholarship.
  • The boy who was clever got a scholarship. 

In the first sentence, 'clever' is an adjective which is modifying the noun 'boy'. In the second sentence, 'who was clever' is a clause and it is modifying the same noun 'boy'. So, 'who was clever' is an adjective clause.

What is an adjective clause? 

An adjective clause is a group of words that has a subject and a finite verb and that modifies a noun or pronoun of the main clause. 

Adjective Clause Pronouns

An adjective clause begins with relative pronouns. So, the relative pronouns are also called adjective clause pronouns. The adjective clause pronouns are: who, whom, whosewhich that.

It is very important to know that the adjective clause pronouns can function as subject, object, or possessive. They are also personal and impersonal. Look at the table and the explanation following it.

Subject
Object
Possessive
who
whom
whose
which
which
of which
that
that
x

Easy Examples of Adjective Clauses

Adjective clauses most often replace an adjective. Here are some examples for your better understanding. The explanations are in the brackets. 

Blind people have a strong mind. (Blind=Adjective)
People who are blind have a strong mind. (who are blind=Adjective clause)
His father is a rich man. (rich=adjective)
His father is a man who is rich. (who is rich=adjective clause)
Ripe mangoes taste sweet. (Ripe=adjective)
Mangoes which are ripe taste sweet. (which are ripe=adjective clause)

Types of Adjective Clauses

Adjective clauses are classified based on the relative pronouns they begin with. There are mainly five types of adjective clauses in English. 

1. Adjective Clause with Relative Pronoun as Subject

Relative pronouns can be the subject of an adjective clause. 

  • This is the man who called you yesterday
  • The baby which came here is my brother. 
  • He tells a tale that sounds untrue

2. Adjective Clause with Relative Pronoun as Object of Verb

Relative pronouns can be the object of an adjective clause. 

  • The book which I bought is lost. 
  • The migratory bird that he shot down was beautiful. 
  • The girl whom you met in the hospital is my cousin. 

3. Adjective Clause with Relative Pronoun as Object of Preposition

Relative pronouns can be the object of preposition of an adjective clause. 

  • The house in which he lives is beautiful. 
  • Where is the man about whom you were talking?

4. Adjective Clause with Relative Pronoun as Possessive

Relative pronouns can be in the possessive forms. 

  • The boy whose father is a doctor is brilliant. 

5. Adjective Clause with When, Where & Why

Sometimes when, where, why, and how can be used as relative pronouns. Then they form adjective clauses. 

  • I remember the place where I was born.
  • I knew the reason why he was angry.
  • Sunday is the time when the week begins.  

Adverbial Clause

When a sub-ordinate clause does the function of an adverb, it is called an adverbial clause. There are mainly nine types of adverbial clauses. They are:

  • Adverbial Clause of Time
  • Adverbial Clause of Place
  • Adverbial Clause of Concession
  • Adverbial Clause of Condition
  • Adverbial Clause of Comparison
  • Adverbial Clause of Degree
  • Adverbial Clause of Reason
  • Adverbial Clause of Result
  • Adverbial Clause of Purpose

1. Adverbial Clause of Time

If a clause indicates time, it is called adverbial clause of time. An adverbial clause of time begins with the conjunctions when, while, after, before, till, until, as, as soon as

  • Strike while the iron is hot
  • They were asked to wait till the signal was given.
  • Wait until I return.

2. Adverbial Clause of Place

If a clause indicates place, it is called adverbial clause of place. An adverbial clause of place begins with the conjunctions 'where' and 'wherever'

  • I shall go where he lives
  • You may go wherever you like.

3. Adverbial Clause of Concession

When two clauses expressing two contrasted ideas are joined together with a sub-ordinate conjunction (though or although), the sub-ordinate clause is called adverbial clauses of concession. This is called so because it admits (or concedes) some fact or supposition. An adverbial clause of concession begins with the conjunctions though, although & even though.

  • Though he is poor, he is happy. 
  • He did not come although I invited him.

4. Adverbial Clause of Condition

An adverbial clause of condition is a sub-ordinate clause that expresses condition. An adverbial clause of condition begins with the conjunctions 'if'.

  • If you read, you will learn. 
  • If winter comes, can spring be far behind? 

You cannot get the chance to be enrolled in a university if you do not study hard. 

5. Adverbial Clause of Comparison

An adverbial clause of comparison begins with 'than' and it modifies the comparative adjective or adverb in the main clause. Read the following examples. 

  • The prices were a great deal higher than I had anticipated
  • You are wiser than your brother is

6. Adverbial Clause of Degree

An adverbial clause of degree begins with 'as' and it modifies the adjective or adverb in the main clause. Read the following examples. 

  • He is as tall as his father is
  • She ate as much as she could.
  • A dog cannot run so fast as a deer can

7. Adverbial Clause of Reason

Adverbial clause of reason begins with as, since, or because

  • He often visits Spain because he likes the climate
  • As he was ill, he did not go to school.
  • As I trust myself, I don't need to write a number on it.

8. Adverbial Clause of Result

An adverbial clause of result begins with 'that' and it modifies the adjective or adverb in the main clause. Read the following examples. 

  • He is so weak that he cannot walk
  • The poles are so cold that none can live there.
  • She is so wise that nobody can cheat her.

9. Adverbial Clause of Purpose

An adverbial clause of purpose begins with that, so that, or in order that

  • We read that we may learn.
  • We read so that we may learn.
  • We read in order that we may learn

Select the correct answer

Q1. Where he lives is a mystery. Here “Where he lives” is a/an-----.
noun
adverbial
principle
adjective
Q2. It's a mystery where he works. Here “where he works” is a/an-----.
noun clause
adjective clause
adverbial clause
principal clause
Q3. This is the book I lost. Here 'I lost' is-----.
Noun clause
An adjective clause
An adverbial clause
None of the three
Q4. I know where he lives. Here “where he lives” is a/an-----.
a noun clause
an adjective clause
an adverbial clause
a principal cause
Q5. 'Do or die' is a-----sentence.
simple
complex
compound
none
Q6. He asked me who got the Noble Prize in literature in 2012. Here “who got the Noble Prize in literature in 2012” is a/an-----.
an adverbial clause
an adjective clause
a participle clause
a noun clause
Q7. You cannot get the chance to be enrolled in a university unless you study hard. Here “unless you study hard” is a/an-----.
a noun clause
an adverbial clause
an adjective clause
a participle clause
Q8. ‘The table has four legs.’ This is the example of-----clause.
Dependent
Subordinate
Independent
Complex
Q9. I know how he struggled against poverty. Here “how he struggled against poverty” is a/an-----.
Noun clause
Adjective clause
Main clause
Adverbial clause
Q10. I know the boy who will win. Here “who will win” is a/an-----.
an adverbial clause
a noun clause
adjective clause
principal clause
Q11. The prices were a great deal higher than I had anticipated. Here “than I had anticipated” is a/an-----.
Noun Clause
Adjective Clause
Adverbial Clause
Main Clause
Q12. We all know that humans are mortal. Here “that humans are mortal” is a/an-----.
an adjective clause
a noun clause
an adverb clause
principal clause
Q13. I enquire how he lost his money. Here “how he lost his money” is a/an-----.
an adverb clause of reason
a noun clause
an adjective clause
an adverb clause of result
Q14. The migratory bird that he shot down was beautiful. Here “that he shot down” is a/an-----.
a noun clause with relative pronoun as subject
an adverb clause of degree
an adjective clause with relative pronoun as possessive
an adjective clause with relative pronoun as object
Q15. ‘As I trust myself, I don't need to write a number on it.’ Here “As I trust myself” is a/an-----.
adjective clause
noun clause
adverb clause
none of the above