4.3 Sentence and clause level grammar: Sentence Structure

Sentences may be made up of a single clause, or two or more clauses which are joined together by conjunctions.

Note: The word sentence is a grammatical term which is used to show a complete unit of thought in written texts. Capital letters, commas, full stops and other punctuation marks indicate the boundaries of the units. They take the place of intonation and pauses which we use when speaking.

(i) Simple Sentences


A simple sentence consists of a single clause and has a subject and a verb. It has the same structure as a clause in that there may also be an object and the circumstances surrounding the event. However neither of these elements is necessary and a sentence (or a clause) can be complete with just a subject (implied or expressed) and a verb.

The subjects of sentences and clauses are the people, places, things or ideas carrying out the actions or happenings - the 'doings' or 'beings'. (The 'doings' and 'beings' are expressed by the verbs.)

The objects of sentences and clauses are the people, places, things or ideas receiving the actions, having the action(s) done to them.

Note: The word 'object' in this context is a grammatical term and the object of a clause or sentence can be a person as well as a thing or idea.

e.g Subject + Verb/verb group + Obj(s)/Circs/Complement
  The dog   bit   the child (object)
  I   study   Law(obj.) at university (circ)
  She   can sing    
  You   are walking   too quickly (circs)
  They   are   students (complement)
  He   has   a big smile (complement)
Note: The term complement (not object) is used with relating verbs (such as: be, become, seem, possess, because the information after the verb is being linked to the subject and is not the receiver of any action.

(ii) Compound Sentences

  A compound sentence consists of two clauses (or simple sentences) joined together by a co-ordinating conjunction (a linking word). The clauses are independent clauses (also known as main or principal clauses because they contain ideas which make sense by themselves and are of equal status.
eg They wanted to leave immediately, BUT decided to wait until next week.
The wind blew strongly last night AND it caused a lot of damage.

(iii) Complex Sentences

  A complex sentence is composed of a dependent clause (also known as a subordinate clause) which is connected to an independent clause by a subordinating conjunction. A dependent clause is NOT of equal status to the one in the independent clause. It is subordinate to the meaning in the independent clause; it depends on the main clause to make sense.
eg WHEREAS students used to have a great deal of leisure time, nowadays many have to fit in their studies around a full time or part time job.
THUS: WHEREAS students used to have a great deal of leisure time. does not contain a complete thought, and is therefore not a complete sentence. This dependent clause needs the main clause to make sense and to complete the idea being expressed.
BUT: The main clause: Nowadays many [students] have to fit in their studies around a full time or part time job can stand by itself independently without the subordinate clause and still make sense by expressing a complete thought.
Note: At university level compound and complex sentences tend to be used more often than simple ones as they are more sophisticated in style, particularly complex ones, and can express relationships between ideas more effectively and succintly. Don't overuse subordination however, as its complexity can make your ideas too hard to follow. Keep sentences manageable - two to three clauses per sentence is a useful guideline.
  Examples of subordinating conjunctions: because, although, while, whereas, since, if
See CONJUNCTIONS for a full list of these and of co-ordinating conjunctions.
Another group of subordinate clauses are relative clauses (also known as adjectival clauses). These clauses give more information about the noun.
eg I can't put down the book [which/that] I bought yesterday.
... I bought yesterday gives more information about the book.
In English we don't always need to express the relative pronoun, so which or that are optional in this sentence.

Another way of combining messages is with saying or sensing verbs, where there is often a clause (or clauses) to show what was said or sensed. These clauses may be reported or quoted in direct speech.

eg "No, I won't," retorted the Red Queen - DIRECT SPEECH (direct quotation)
The Red Queen said she wouldn't do it. INDIRECT SPEECH (with saying verb)
Alice thought she was rather strange. INDIRECT SPEECH (with sensing verb)

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