A paragraph is a number of related sentences focused on an idea. It forms a part of a larger piece of writing such as a composition. The basic aim of a paragraph is to communicate an idea in a clear and effective way. It aims to discuss one aspect of the subject or topic.
The length of a paragraph varies according to the simplicity or complexity of the main idea. A paragraph should not be so short that the idea talked about is inadequately described or explained. It should not be so long either that it covers more than what is intended.
A paragraph with a length of between five and eight sentences is normally sufficient to expand on an idea. Anything more than this may be better organized into a separate paragraph. This ensures not more than one idea is covered in one paragraph. After all, the purpose of paragraphs is to separate ideas. A new paragraph means a new idea is being dealt with.
A paragraph starts off with a topic sentence. This first sentence introduces the main idea of the paragraph. The sentences that follow the topic sentence discuss the idea. Some of the things the writer does here, for example, include expanding on the idea, establishing the facts, providing details, and quoting examples. They must strictly be about the idea and not deviate to something else.
Coherence of a paragraph is important to maintain continuity. This can be accomplished by making use of sentence connectors, such as introductory words or phrases, as follow:
In addition, ...; Furthermore, ...; Moreover, ...; On top of that, ...
Consequently, ...; As a result, ...; hence, therefore,
On the contrary,...; Nevertheless, ...; Conversely, ...; Otherwise, ...
For instance, ...; For example,...; Take the case of...
Likewise, ...; Similarly, ...; To conclude, ...: In short, ...
Once, still, later, finally, indeed, in fact.
The idea here is to break the topic into smaller units, each of which is used as a basis for your paragraph.
The last sentence in a paragraph is the concluding sentence of the paragraph. Use different words to restate the idea as introduced by the topic sentence in this concluding sentence – a summary of what has been discussed.