A sentence is a group of words in a text that expresses a complete thought. It includes a subject with or without a determiner, a verb phrase and a complement. Sentences can be simple, compound, or complex. A traditional scheme classifies sentences by the number and type of clauses with finite verbs. A simple sentence contains a single independent clause; a compound sentence contains two or more independent clauses that are joined together by coordinating conjunctions or marks of punctuation; and a complex-compound sentence contains a main independent clause with one or more dependent clauses.
A paragraph is a unit of writing that develops ONE main idea through a series of related sentences. This main idea is introduced in the topic sentence of the paragraph, and developed through the sentences that follow.
Paragraphs are the building blocks of papers, and a good one is well-planned. As with any structure, if a paragraph isn’t built on a solid foundation, it will fall apart.
When constructing your paragraphs, you should consider how the sentences within the paragraph will work together to support a particular point of view or argument. A paragraph that compares or contrasts two things, for example, can be divided into two separate paragraphs if you want to focus on different aspects of each comparison. You can also use parallel structures to make it easier for readers to see how your paragraphs relate to one another. The more you can unify your paragraphs, the clearer your argument will be.