As I was proofreading something recently, it occurred to me that discussions of punctuation and grammar contain relatively little about the period. If you go looking for information on using periods, you will mostly find technical advice about formatting. Such editorial advice is crucial, but not necessarily of primary interest to the writer. The obvious reason that writers don’t worry much about periods is that their use is pretty straightforward: we use a period after a complete sentence. The period has none of the apparent complexity of the semicolon, the colon, the dash (more on the dash here), or the comma (more on the comma here, here, here, and here). But that relative simplicity doesn’t mean that the decision to use a period isn’t consequential. A period makes evident key authorial decisions: whether to say a lot or a little before stopping; whether to be assertive or interrogative when raising questions; or whether to insert a full stop or just the rolling stop achieved by other types of punctuation. I certainly don’t want to problematize the one piece of punctuation that everyone feels good about, but the ways that we stop in our writing are worth some consideration.
Short vs. long sentences. Any time we use a period, we are deciding whether we want a short or long sentence. If we are generous with our periods, we will be writing clipped sentences; if we are stingy, on the other hand, we will end up with sprawling sentences. Neither is better. The previous sentence, for instance, is short because I want to emphasize it. And its brevity is enhanced by the fact that it follows a longer set of sentences with a semicolon framing their double-barrelled structure. It generally works well to use short sentences for emphasis and longer ones for depth. If we go too far in either direction, the reader will begin to suffer. Too many long sentences coming one after another—even if they are individually well structured—can be fatiguing for the reader. Too many short sentences will disorient the reader since not everything can warrant special emphasis. Those short sentences will inevitably contain unimportant things; the reader’s confidence in you can be undermined if you appear to be emphasizing the insignificant. Creating a healthy mix of short and long sentences can be the best thing for your paragraphs.
Direct vs. indirect questions. What is the impact of asking a question as compared with stating that a question exists? When raising questions in our work, we have to decide whether to use a direct question—i.e., one that ends with a question mark—or an indirect question, i.e., one that ends with a period. When we use too many direct questions, our readers may start to see us as having more questions than actual strategies for answering those questions. An indirect question gives us the ability to articulate a question, which is obviously essential to academic writing, while also indicating our plans for addressing the question.
Full stop vs. rolling stop. As a hopeless over-user of colons and semicolons in my own writing, I have a particular interest in this question. During editing, I often find long strings of sentences, all of which are connected by semicolons. An over-reliance on the rolling stop is a bit like an over-reliance on transition words: it tries to impose flow rather than establishing it. Genuine flow will involve the use of some colons and semicolons; there’s nothing wrong with nudging your reader towards the next sentence. The semicolon says that the next sentence is intimately connected to this one; the colon says that the next sentence completes what is being said in this one. Those relationships are emphasized by the punctuation choice, but the punctuation alone won’t create that relationship. The choice between a full and a rolling stop should be consciously based on an understanding of the nature of the connection between sentences.
In sum, if you understand what is requisite for a complete sentence, your use of periods will be perfectly correct. But thinking about how and why we end sentences can still be a useful avenue for improving the flow in your writing.