Clauses and sentences

This section covers:

To understand clause and sentence structure, it is useful to know the terms for parts of a clause.

Term Example

A subject is the person or thing that performs the action of the verb, or is experiencing the thought, feeling or relationship of the verb

I [subject] love fresh truffles.

That plan [subject] was endorsed yesterday.

An object is the person or thing affected by the verb, or its goal

The dingo mauled the bettong [object].

Their lecturer explained the idea [object].

An adjunct is an adverbial unit that modifies the verb

Choose your words carefully.

We left the camp at sunrise.

A clause is a group of words with a subject and a verb

They were running.

I couldn’t speak.

The predicate of a clause consists of the verb plus its object and/or adjunct, which together say something about the subject

The exam had difficult questions.

The girl ran down the hill.

An independent clause can stand alone as a sentence, or may have dependent clauses attached to it

The moon came through the clouds.

As we watched, the moon came through the clouds.

A dependent clause cannot stand alone as a sentence As we watched, the moon came through the clouds.

Clause structure

Clauses are the basic unit of any sentence. They consist of 2 key elements:

  • a subject (ie the actor or agent of the verb)
  • a predicate, which consists of a verb and usually some information about its goal or what it acts upon (ie the object).

Simple sentences can be made of a single clause:

diagram of how a clause breaks into subject and predicate and the predicate can be broken up into verb phrase, noun phrase and propositional phrase

Complex sentences consist of more than 1 clause:

A diagram showing how some complex sentences can be thought of as a main clause and a dependent clause

See also Subordination.

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Types of sentences

English has 4 different types of sentences with different functions. The function dictates the order of the key clause elements within the sentence. The 4 types of sentences are:

  • statement – this is the most common form of sentence. It uses a standard order of subject  →  verb  →  object or subject  →  verb  →  adjunct (adverb or prepositional phrase)
The clerk [subject] delivered [verb] the mail [object].

The time [subject] passed [verb] like lightning [adjunct/prepositional phrase].

  • command – a command usually begins with a verb and leaves out the subject
Stay [verb (imperative)] still [adverb]!

Consider [verb] the alternative [object].

  • question – questions take 2 forms
    • open questions, which start with Where? When? Which? Who? or How? to elicit information
    • closed questions, where often only yes or no answers are expected
When did you arrive?     How did you get here?   [open questions requiring further information]

Was the train on time?     Have you had lunch yet?   [closed questions with yes/no answer]

  • exclamation – exclamations are usually short phrases. They can begin with question words such as What or How, but can take other forms, especially in less formal writing
How time flies!     What a good idea!     Here we go!     Nothing like it!     No way!
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Clause connections

When a sentence has more than 1 clause, the clauses can be joined together either as coordinated clauses of equal status (coordination) or as a main clause and dependent clauses (subordination).


Coordinated clauses are equal in status. They are joined by and, but, however, or or nor:

  • And is used to add additional information.
  • But and however are used to give contrasting information.
  • Or and nor are used to give positive or negative alternatives.
We were keen to continue the bushwalk and find the smugglers cave. 

We were keen to continue the bushwalk, but the smugglers cave was too far.

We were keen to continue the bushwalk; however, the group decided they would set up camp first.

We could continue the bushwalk or camp for the night.

We could neither keep walking nor find shelter from the rain.

Note that however used in this way should be preceded by a semicolon or a full stop, not a comma:

I wanted to have lunch; however, I was running late.
I wanted to have lunch, however, I was running late.


Clauses related by subordination are unequal in status: the subordinate clause depends on the main clause. Subordinate clauses can be joined to the main clause with:

  • adverbial subordinators – such as although, because, since, until, when
We walked fast because it was raining.

We will keep walking until we find a suitable spot.   

  • complement links – that, what, how, if (used with verbs such as say, think, ask, wonder)
We thought that it was a good idea.

He wondered what he should do.

  • relative pronouns – that, which, who, whom.

    Subordinate clauses joined by relative pronouns (often called relative clauses) can be defining or nondefining. Defining clauses are vital for the meaning of the sentence; nondefining (relative) clauses can be deleted without loss of meaning:

The children, who were hungry, ate everything on the plate. [nondefining] 

The children who were hungry ate everything on the plate. [defining]

[The first sentence is about all the children: every child ate up, and their hunger is incidental. The second statement makes it just the hungry children who ate up, and the sentence defines that subset of them.]

See also That and which, Who and whom.

Did you know? 

With is not a subordinator but a preposition. It is often used in bureaucratic writing to join clauses, but it is clearer to use the appropriate conjunction:

The smoke haze is affecting civilian health, with increasing admissions to Sydney hospitals.

is better as

The smoke haze is affecting civilian health, and admissions to Sydney hospitals are increasing.

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