A sentence is a unit of speech whose grammatical structure conforms to the laws of the language and serves as the chief means of conveying a thought. A sentence is not only a means of communicating something about reality but also a means of showing the speaker’s attitude to it.
Classification of sentences
Communicatively, sentences may be subdivided into four major syntactical classes.
Declarative sentences, or statements.
They are sentences which give information, or state facts in the affirmative or negative. They are mostly characterized by the subject-predicate word order and generally pronounced with a falling intonation:
§ The press conference had gone off fairly well.
§ Nobody was able to answer the question.
(2) Interrogative sentences, or questions. They are typically sentences by which someone asks his hearer to give information. They are subdivided into the following groups:
(a) general questions (‘yes-no’ questions). They are usually formed by placing an auxiliary verb before the subject and giving the sentence a rising intonation.
§ Have you done it?
§ Did she go there?
(b) special questions (WH-questions). They are formed with the aid of one of the following interrogative words: who/whom/whose, what, which, where, how, why. As a rule the interrogative word comes first with the auxiliary following it, yet when the question refers to the subject no auxiliary is needed.
§ Why did you do that?
§ Who told you that?
(c) alternative questions. The alternative question expects as an answer one or more alternative mentioned in the question. There are two types of alternative questions, the first resembling a general question, and the second a special question:
§ Would you like chocolate or strawberry ice-cream?
§ Which ice-cream would you like? Chocolate or strawberry?
(d) disjunctive questions (tag questions). They ask for confirmation of the truth of the statement. The tag question added to the end of the statement consists of an auxiliary verb plus pronoun, with or without a negative particle. In most cases if the statement is positive, the tag question is negative, and vice versa:
§ He likes his job, doesn’t he?
§ Nobody was watching me, were they?
(3) Imperative sentences, or commands. They are aimed at getting someone to do something.
§ Shut the door.
§ Just look at this mess.
A command differs from a statement in that (i) it has no subject; (ii)it has a verb in the imperative:
§ Be careful!
§ Please hurry up.
(4) Exclamatory sentences, or exclamations. They are used to express the speaker’s feeling or attitude. The exclamation as a sentence type begins with What or How. In contrast to WH-questions, there is generally no subject-predicate inversion:
§ What a good dinner she cooked!
§ How delightful her manners are!
§ How beautifully she dances!
According to their structure, sentences may be simple and composite.
Sentences with only one subject-predicate group are called simple.
§ I stared for a moment at Arnold’s face.
Sentences with more than one subject-predicate are called composite. They are further subdivided into (1) compound and (2) complex:
(1) He waved his hand and I went in through the half-open gate.
(2) I laid the hundred dollar bill the Indian had given me down on the desk.
Simple sentences may be subdivided into two-member and one-member sentences.
Two-member sentences contain both principal parts – the subject and the predicate.
§ The door was shut.
§ So far I had only made four mistakes.
A two-member sentence may be complete and incomplete. It is completewhen it has a subject and a predicate.
§ I sat still for a moment.
The sentence is incomplete, or elliptical when one of the principal members or both are omitted. The missing part (or parts) of such sentences can be easily understood from the context or the situation. Elliptical sentences are used in colloquial style, most commonly in dialogue. They enable the speaker to avoid repetition and focus attention on new material.
§ Did somebody phone you? – Carol.
§ “Any ideas?” he asked softly. – About what?
There are sentences which comprise only one central element which can be identified neither with the subject nor with the predicate. These sentences are called one-member sentences.
§ The floor was covered with green and grey linoleum in squares. The wails were painted white. A clean room! Marvellous!
§ My poor lamb! To think of the work you’ll have getting straight in that stupid Vale View.
Both one-member and two-member sentences may be extended and unextended.
An unextended sentence contains no other parts but the subject and the predicate (or only one central member in case of one-member sentences).
§ I knocked. Silence.
An extended sentence contains not only the main members – the subject and the predicate (or the central element in a one-member sentence), but one or more secondary members: objects, attributes or adverbial modifiers.
§ The garage was full of nothing. Rubbish, garbage, junk, rusted gardening tools, old cans, plenty of those, in cartons.