A good composition is made up of paragraphs.a paragraph is a distinct unit in prose writing; it is, in fact, the logical development of a single idea. Generally a paragraph contains about two to ten sentences. Shorter paragraphs may be used to emphasize a particular point; while, larger paragraphs are used in professional or technical writing. a good paragraph must have unity, coherence and variety.
UNITY
The theme of the paragraphs is often expressed in one sentence which contains the topic of the paragraph. It is called the TOPIC SENTENCE and normally it is placed in the beginning of the paragraph. The topic sentence is built up or supported by relevant information explaining or amplifying the theme of the paragraph. Every sentence in a paragraph must be closely connected with the main topic in order to achieve unity, or single trend of thought.
NOTE :-- how the unity of ideas is achieved in the following paragraph: just when did football begin ? Many theories have been put forward, but most of them are probably guesswork. round ball-shaped objects have been found in the graves of people such as the ancient Egyptians and were obviously used as playthings. It's easy to think that sooner or later some boy would start to kick this ball about, just as lots of boys today kick old tin cans about in a recreation ground or even along the gutter in the roadway. Go a little further and, before you know what has happened, another boy is trying to take the 'ball' away from the first boy and then others join in, and within no time you have two sides kicking away; and a new game is born.
COHERENCE
A paragraph is a single unit of thought, the ideas in it must be so arranged as to make their logical relation very clear. Thus every sentence should be linked to the one that goes before. There are four significant devices which help to maintain coherence in a paragraph. They are - pronouns, repetition, synonyms and linking words.
PRONOUNS : a pronoun is a substitute for a noun and it serves as a reminder f the noun in the previous sentences. The use of pronouns, in this way, helps to maintain continuity of thought.
REPETITION : the repetition of some specific words or ideas serves to make this paragraph coherent, besides emphasising the author's point of view. However, repetition should not make the paragraph monotonous.
SYNONYMS : this device helps the author avoid excessive repetition by using substitutes (synonyms) for words already used.
CONNECTIVES : connective words or phrases are used at the beginning of a sentence to show a relationship between the sentences in a paragraph. Some of such connectives are : and, but, therefore, as a result, consequently, finally, etc.
The following paragraph illustrates what is said above. In this paragraph, the topic sentences is the first sentences, which is developed by explaining and examples.
In films, sound effects play the part of words. For example, the sound of footsteps followed by the slam of a door are phrases that carry a certain amount of information. Once the sounds are prefaced or followed by a line of dialogue, the 'sentence' is complete. We know who is performing this action, and why; and a clear picture is formed in our mind's eye. Sound effects also play the part of words when they set a scene or establish a mood --- a function often performed by music. They may even serve as figures of speech or metaphors; a character in drama. In radio, as in film, fade-outs and fade-ins form part of basic grammar. Such devices may be used simply as punctuation, to mark time lapse or a change of location. Their most valuable function, however, is not to punctuate but to add perspective to a scene. By gradually increasing or diminishing the volume of a sound, for example, the producer can create an illusion of movement in space.
VARIETY
A good paragraph keeps the interest of the reader. It's avoids monotony by having recourse to variety of sentences. It contains a variety of words, images, examples and sentences. The writer ensures that he uses both short and long sentences; and sentences of different structures.
READ The following paragraph and examine how the author maintains variety. The topic sentence is developed by using the technique of enumeration---- that is, by enumerating some of the ways in which a scientific society can be stable. Note the use of the connectives such as : The first of these............, the second condition .............the third condition............. the fourth condition....
My conclusion is that a scientific society can be stable, given certain conditions. The first of these is a single government of the whole world, possessing a monopoly of armed force; and therefore able to enforce peace. The second condition is a general diffusion of prosperity, so that there is no occasion for envy of one part of the world by another, The third condition (which supposes the second fulfilled) is a low birth-rate everywhere, so that the population of the world becomes stationary or nearly so. The fourth condition is the provision for individual initiative both in work and play, and the greatest diffusion of power compatible with maintaining the necessary political and economic framework.