Explanation:

2. In each paragraph of an essay, one particular idea or topic is developed and explained. In order to successfully do so, however, it is essential that the paragraph be written in a unified and coherent manner.

A unified paragraph must follow the idea mentioned in the topic sentence and must not deviate from it. For a further explanation on topic sentences, see the Write Right on Topic Sentences.

A coherent paragraph has sentences that all logically follow each other; they are not isolated thoughts. Coherence can be achieved in several ways. First, using transitions helps connect ideas from one sentence to the next. For more on transitions, see the Write Right on Transitions. Second, ordering thoughts in numerical sequence helps to direct the reader from one point to the next. Third, structuring each paragraph according to one of the following patterns helps to organize sentences: general to particular; particular to general; whole to parts; question to answer; or effect to cause.

Remember that a paragraph should have enough sentences so that the main idea of the topic sentence is completely developed. Generalizations should be supported with examples or illustrations. Also, details and descriptions help the reader to understand what you mean. Don't ever assume that the reader can read your mind: be specific enough to develop your ideas thoroughly, but avoid repetition