Unity – a paragraph has unity when its sentences clarify or support the main idea.  The sentence that contains the main idea of a paragraph is the topic sentence.  The topic sentence helps the writer stay focused on the main idea of the paragraph.

Coherence – a paragraph has coherence when its sentences relate to each other in content, grammatical construction, and choice of words.

Parallelism – parallel structure also helps you achieve coherence.  When grammatically equivalent forms are used, parallelism exists.  Consider the following example of nonparallel and parallel constructions:

• Nonparallel – the position is prestigious, challenging and the money is not bad
• Parallel – the position offers prestige, challenge, and money