A sentence expresses a complete idea that includes a subject and a verb. Sentences may be declarative, interrogative, imperative or exclamatory. A subject is usually a noun, pronoun or noun phrase but can also be an adjective, adverb or noun clause. The verb is what completes the sentence; it can be either simple, compound or complex. The object of the verb forms the complement or the indirect object; this is usually a noun, adverb or noun phrase.
A paragraph may contain a series of short illustrations of one general point; it may compare and contrast two or more things; it might classify items into categories; or it might describe causes and effects. Paragraphs should be organized logically and supported by details and examples. The details should be clearly related to the controlling idea of the paragraph (often stated in its topic sentence). Paragraphs should use transition sentences to help the reader move logically from one idea to another.
The final sentence of a paragraph should restate the paragraph’s main idea and summarize the new information from the support sentences. This sentence should be concise; overlong concluding statements can come across as padding. Some writers conclude paragraphs by listing all the major points made in the support sentences; this can work if it is done with care, as it helps ensure that the author has not omitted any important information. However, this can be confusing for the reader. A better approach is to write a paragraph with just one main idea and to include a sentence that reminds the reader of this main idea.