What is a paragraph?
I always tell my students that a paragraph is a group of sentences that work together to develop an idea. How large or small that idea may be depends on what it is. On average there are usually between five to ten sentences in a paragraph. There could be fewer or more, depending on the type of writing that a person is doing. You'll notice that paragraphs in a sentence are sometimes composed of just one or two sentences. Sentences in a novel or an essay could number well over 20 or 30 sentences. The author is one variable. Then you have to consider the format, the audience, the purpose, the topic, and an assortment of other things when judging an appropriate length for a paragraph.
A basic all-purpose paragraph is five to six sentences in length, and it may or not be indented. The indentation is the small blank space that appears just before the first sentence, which is usually the topic sentence. This is then then followed by three or four sentences that support the topic sentence. The paragraph ends with a concluding sentence. This is the structure that many (but not all) American English teachers expect from their students.
This is what a paragraph looks like:
(indent) Immigration contributes to the overall health of the American economy. Despite recent concerns expressed about illegal and some legal immigration to the United States, this country has largely benefited from the skills, talents, and ambition that immigrants bring with them. American businesses gain from a good source of affordable labor, while town and cities are revitalized by immigrant families who strengthen communities through civic participation and the generation of new economic activity. The United States must continue to welcome new arrivals and help those who already here; otherwise, the country will lose the advantages it has over other industrialized countries who compete against us in the global marketplace and seek to recruit from a vast pool of unskilled and skilled global workers.
So that's a paragraph. It has a topic sentence, supporting sentences, and a concluding sentence. Those three elements are essential when writing a paragraph. Paragraphs are often indented, but it's common practice these days to use what is called a "full-block" style and not indent at all. Now let's look at the paragraph above in more detail.
The first sentence of a paragraph is the topic sentence. It doesn't have to be the first sentence. It could be the second sentence or even the last sentence, but if you are fairly new to the writing process, when you write a paragraph, I strongly recommend that you make the first sentence the topic sentence.
The topic sentence states the main idea for the entire paragraph. In the example above the topic sentence is "Immigration contributes to the overall health of the American economy." This identifies sentence identifies exactly what the subject of the paragraph is and it takes a position or provides some focus for the rest of the paragraph. If the other parts of the paragraph aren't about immigration and economic development in the United States, the paragraph loses its focus and strays off topic.
The supporting sentences provide evidence or support for the idea stated in the topic sentence. Three or four sentences are generally necessary in order to provide adequate support. These sentences may be used later in the development of additional sections of an essay assignment if that is what you are working on. Even if you aren't working on an essay assignment, I think it's a good idea to think of a single paragraph as a potential first paragraph for an essay or a research paper. That way, you'll know that whatever you state in the first paragraph can be further substantiated with additional information.
The last sentence is the concluding sentence. This can be a difficult sentence for some students to write because it must do two or three things: it summarizes the entire paragraph and it refers the reader's attention to whatever is claimed in the topic sentence. When there are additional paragraphs that follow, the concluding sentence can also serve as a transitional element that leads into the first sentence in the next paragraph. That's a lot of responsibility for one sentence!
I am going to add a side note here. English teachers are notorious for disagreeing with each other on this or that point when it comes to writing, so anything I've said so far or will say in later lessons is likely to be countered by another teacher's opposing opinion on writing. That's the way English teachers are. They have their own ways of doing things, so what I'm telling now may differ from something your English teacher tells you to do. But it's good to get a variety of opinions when learning something new, isn't it? Ultimately, you'll pick and choose from among the best instructional techniques and do what you think works best. That said....let's continue.
The next lesson is on the topic sentence.