Formal Definition of Sentence
A sentence is a set of words that is complete in itself, typically containing a subject and predicate, conveying a statement, question, exclamation, or command, and consisting of a main clause and sometimes one or more subordinate clauses. (Source: Oxford Dictionary)
A sentence can convey a statement, a question, an exclamation, or a command. There are four types of sentence:
1) A Declarative Sentence.
A declarative sentence states a fact and ends with a period (full stop). For example:
- He has every attribute of a dog except loyalty. (Politician Thomas P Gore)
- I wonder if other dogs think poodles are members of a weird religious cult. (Comedian Rita Rudner)
(Remember that a statement which contains an indirect question (like this example) is not a question.)
2) An Imperative Sentence.
An imperative sentence is a command or a polite request. It ends with an exclamation mark or a period (full stop). For example:
- When a dog runs at you, whistle for him. (Philosopher Henry David Thoreau, 1817-1862)
3) An Interrogative Sentence.
An interrogative sentence asks a question and ends with a question mark. For example:
- Who knew that dog saliva can mend a broken heart? (Author Jennifer Neal)
4) An Exclamatory Sentence.
An exclamatory sentence expresses excitement or emotion. It ends with an exclamation mark. For example:
- In Washington, it’s dog eat dog. In academia, it’s exactly the opposite! (Politician Robert Reich)