A paragraph is the basic unit of composition. It can be an independent piece of writing, or part of a composition and so on. A well-written paragraph must have three indispensable elements — topic sentence, developers and terminator. These parts of the paragraph are otherwise known as the beginning, the middle and the conclusion. The capability of exploiting these elements much help the writer develop a paragraph in a well-organised and well-developed way.
The topic sentence is usually the first sentence in a paragraph. It is the single most important sentence through which the writer tells the reader what s/he is developing in the subsequent sentence excepting the last one in the paragraph.
The developers consist of the sentence placed between the topic sentence and the last sentence in a paragraph. They develop the topic sentence through elaboration, exemplification, classification and so forth. That is, they detail, expand and support the idea put forward in the topic. The terminator is the last sentence in a well-written paragraph. It logically concludes the ideas developed through the developers of the paragraph.
All things considered, sentences used in a paragraph must be written in lapidary style. It must be terse, succinct and economical. Do not make any spidery writing and try to avoid flowery use of words. Wordiness and long-winded sentences must be avoided. A standard sentence must be within 10 to 12 words.