Four Functions of Paragraphs


Paragraphs are the workhorses of writing. Their job is to make four things happen. These four functions make a paragraph understandable. Once students know how to use these four functions, they will be able to develop their own paragraphs, unify their focus, and create a coherent document.

Function #1: A paragraph has to introduce the topic and/or provide transitions to the paragraphs that come before and after.

Function #2: A paragraph has to present important facts, data, descriptions, or other highly specific pieces of evidence. Note that a quotation is evidence. Placing it between Function #1 and Function #3 sentences creates a “quotation sandwich.”  Quotation sandwiches help readers understand the evidence and prepare for the claim.

Function #3: A paragraph has to comment on the evidence in #2 above. Facts can not be assumed to “speak for themselves.” It is the job of the paragraph to speak about the importance of the evidence.

Function #4: A paragraph has to return to the central idea of the paper. Using the evidence, it has to expand, enlarge, correct, limit, or nuance the major idea. The thesis grows throughout the paper, and it grows in these sentences.

These are functions. There are four of them. This does not mean that a paragraph has four sentences. An effective paragraph meets the reader’s expectations by performing all four functions. The following paragraph is a simple example of a Four-Function paragraph. Each sentence is labeled according to its function by a  numeral at its beginning.

Readers expect to have information introduced, supported with evidence, enriched with explanations of the evidence, and then related to a controlling idea.

note: Sometimes, a sentence will have several functions. Consider the following example:

Eleven players on this year’s basketball team are 7’6” or taller, a highly unusual collection that promises many victories.

The sentence presents data (the number of players who are tall) and also explains its importance (it promises many victories). The sentence has combined the #2 Function and the #3 Function. Such combinations are common.


Scientific organizations also know the value of using this structure for paragraphs. CERN, the organization that invented the World Wide Web and now operates the Large Hadron Collider, explains the value of basic research through sentences that serve the four functions.  As part of a web site that explains the organization and its research, it offers the paragraph below. Each function is identified by a superscript just as each was identified in the paragraph about a basketball team:

Without all four functions, a writer would leave too much to the reader, who might misunderstand. Putting the meaning in the words on the page controls the risk of a reader substituting her/his ideas for the writer’s. Remember: the four functions are the tools to use to achieve unity, coherence, and development.

What problems does the Four Function model solve? First, it helps writers who "never have enough to say." Often they do not put into words on the page what they know in their heads. By using the model, students find that making their paper "long enough" is no longer a problem. The paper is not just padded and wordy. It meets the expectations of the grading persona who is not going to give credit for what is not in the words on the page.

Writers can clarify their rough drafts by numbering the function(s) of each sentence in each paragraph. When a function has been ignored, it is relatively simple to add the needed material. An even better way to clarify a rough draft is to have someone else -- a reader -- number the function of each sentence. A reader only understands the words on the page, and this will make it easier for her/him to identify what is missing. Each student will probably find that s/he tends to ignore some functions. By numbering the sentences according to their function, they can identify where documents need to be clarified.

1Macomb Community College has an unusual basketball team. 2Of the fifteen players on the roster, eleven are taller than 7’6”. 2This is the tallest group of basketball players on any team in the country. 2Not only are they tall, but each runs a 40 in less than six seconds. 3This speed means that they are both tall and fast, an unusual combination. 4We can reasonably expect our team to win a national title.

1Fundamental science is where new ideas and methods begin that later become commonplace 2from the electric light, which originated in 19-century curiosity about electricity, to the World Wide Web, invented at CERN to allow international teams of particle physicists to communicate more easily. 3No amount of applied research on the candle would have brought us the electric light; no amount of R&D on the telephone would have brought about the Web. 4Science needs the space for curiosity and imagination.