In a structural description of modern English, the Systemic Grammar recognises five grammatical units. These are: the morpheme, the word, the phrase, the clause and the sentence. By this arrangement (from the smallest to the highest), it could be noted that the sentence is the highest in the hierarchy. This shows how important a sentence is in the structure of modem English. For this reason, this article will focus on the sentence—looking at its definition, types and functions.
Definition of Sentence
Although there could be several definitions of the sentence, the simplest form of definition is that it is the basic unit of expression which is made up of units such as a clause, a phrase, word and morpheme. Above all, a sentence expresses a complete thought.
Types of Sentence
The typology of a sentence can be categorised into two—sentence types based on the structure and sentence types based on the functions.
Sentence Types Based on Structure
Based on the structure or grammatical consideration, we can identify five types of sentences: the Simple, Compound, Complex, Compound-complex and Multiple sentences.
The Simple Sentence
A simple sentence is the type that that expresses a single idea and shares the same feature with an independent clause, e.g. My wife is a student.
The Compound Sentence
A compound sentence composes of two simple independent clauses joined together by a coordinate conjunctions e.g. I came to school and I did my test.
The Complex Sentence
A complex sentence is a type of sentence that has one independent clause joined together with one or more dependent clauses e.g. We will win the election because he is a popular candidate.
The Compound-complex Sentence
A compound-complex sentence contains multiple independent clauses and at least one dependent clause. This sentence type contains both conjunctions and subordinators, e.g. This is the woman whose child is sick and she carries a bag.
The Multiple Sentence
The multiple sentence is formed by joining together of multiple ideas (three or more independent clauses) by coordinate conjunctions, e.g. I signed, I sealed and I delivered (signed, sealed and delivered).
Sentence Types Based Functions
Based on their functions, we have the following types of sentences: Declarative, Interrogative, Imperative, Exclamatory, Passive and Negative sentences.
The Declarative Sentence
a declarative sentence is a sentence that makes a statement. This sentence type usually ends with a full stop mark, e.g. Mary is my friend.
The Interrogative Sentence
An interrogative sentence is used to ask a question. This sentence type usually ends with a question mark, e.g. Who is your friend?
The Imperative Sentence
An imperative sentence is used to give a command or directives or to make requests. This sentence type usually ends with an exclamation mark, e.g. Keep quiet!
An exclamatory sentence is used to express sudden emotions or surprises. This sentence type usually ends with an exclamation mark, e.g. Oh my God!
The Passive Sentence
A passive sentence is a sentence type that shows that the subject is acted upon. It is a sentence type that starts with the object, e.g. The assignment was written by me.
The Negative Sentence
A negative sentence changes the meaning of an ordinary sentence to its opposite by the help of the negative particle “not”, e.g. Mary is not my friend.
Note that the last two examples can also be classified as sentence types based on function.