Very often our Grammar books give the following definition of a sentence: “A group of words so arranged as to express a complete thought is called a sentence”. But the definition is true only in a grammatical sense. Take any isolated sentence from any book, and you cannot fail to see how incomplete it is as it stands. There is the proper number of words, the subject and the predicate – all the grammatical rules have been attended to – yet we feel that in many cases we cannot be quite sure about the real meaning. It can be gathered more fully after reading some more sentences proceeding or going after the sentence in question. When several sentences have been so grouped as to make up a whole thought pattern and together form a more or less independent part of a longer composition, they are called a paragraph.
Each paragraph bears the same relation to an article or a chapter that the sentence does to the paragraph. Almost each paragraph has only a modified independence. For its full meaning it depends upon the other paragraphs in the book. If this is not so, it is not a paragraph but a little essay or story by itself.
The paragraph is itself part of a larger unit of a section or chapter and must, therefore, fit neatly into that unit. II must show some reference to preceding or following paragraphs, perhaps by introducing a series of ideas or by summing up a collection of statements. This means that a paragraph may have not only a topic sentence but also a linking sentence which takes up the thread of previous paragraphs or which states the theme to be developed in the next.
A paragraph consists of a number of sentences which are closely related, and deal with the same topic.
A well-constructed paragraph should possess:
b) logical sequence of thought;
c) variety of length and construction.
By unity we mean that one main theme is dealt with. This theme may be either expressed or understood.
The main information is usually conveyed in the topic sentence . The remainder of the paragraph is an enlargement of this. A paragraph lacks unity when two different topics are treated in it. The topic sentence can be expressed by the first sentence, then comes the development and the last sentence rounds off the whole. The topic sentence may be expanded in a number of ways or it may come as the climax of a series of preparatory sentences. A paragraph cannot be regarded as satisfactory unless the sentences are arranged in a clear and logical order. Each sentence must lead to the following and all must be linked up. The connection between the sentences will be shown by their logical order. Certain pronouns, adverbs and conjunctions are frequently used (thus, hence, further, consequently, however, moreover, etc.).