Punctuation may not seem like a big deal in daily life. Many of us fire off text messages all day with no commas or question marks (or good grammar or even complete words, for that matter, but that’s another topic.) I’m not a stickler for perfection in informal conversation, whether spoken or written. But when you’re writing a book, a school paper, a business letter, or a blog post, following some basic rules helps readers to take you seriously.

Here I’m going to cover the very basics, because I see so many supposedly professional pieces riddled with simple punctuation mistakes. I’m not going to cover everything (sorry, no discussion of the em dash versus the en dash, as I’m still learning that one.)

Period. A period is the little dot at the end of a sentence, like this. It indicates the conclusion of a full thought. Three dots – called an ellipses – does not mean that you’re concluding the sentence more forcefully. Periods prevent run on sentences. If your sentence is really two or more complete thoughts, then you probably need a period. I rarely see periods used too much – it’s usually a lack of periods that’s the problem.

Comma. A comma is a mark, like this one, that indicates a pause or prepositional phrase, or is used to separate items in a series. A discussion of commas can get complex, and I’m not going to go into every possible use. Many writing styles (like AP, Chicago, etc.) have different rules for comma usage. A basic rule of thumb, though, is to use commas if there is a pause in the sentence for the insertion of a side thought or a partial phrase. You can test this by speaking the sentence aloud. If there are places where there seems to be a natural pause or shift, a comma might be needed. Likewise, if there’s no logical pause where you’ve placed a comma, get rid of it.

Exclamation mark. Used for emphasis, or to indicate shouting when writing dialogue. Like this! Overuse of the exclamation mark is what seems to be most common. In nonfiction bold or italics is usually more appropriate when a word or phrase needs emphasis. In fiction, the exclamation mark should be used sparingly – or not at all – in prose and descriptions. And in dialogue, italics, dialog tags, and actions usually help the flow of a story better than an abundance of shouted dialogue. (More about writing dialogue in another post.) And go easy (or avoid completely) multiple exclamation marks to indicate extra-loud shouting. Outside of comic strips, it really doesn’t work.

Question mark. A question mark indicates – you guessed it – a question. Got it? Like periods, this punctuation mark seems to not get used enough. In our quick text or Tweet daily life, punctuation marks take up valuable time and character space. I’m not trying to reform people’s texting habits, but when these shorthand habits spill over into professional or “proper” writing, that becomes a problem. Whether you’re writing a research paper or a novel, if a sentence is asking a question, use the question mark.

Apostrophe. This one can get complicated, so I’ll give the short version here. An apostrophe looks like a comma up in the air, and it’s used to indicate a missing letter or a possessive. The contraction it‘s versus the possessive its can be a stumbling block for even the best writers, so you can read about that in more detail here. The apostrophe is usually seen in words like don‘t (contraction of do not), I‘m (I am), and so forth. Again, lack of use is the biggest problem I see – that, and its improper use with any word ending in the letter s. (See the above link about that.) Dont is not a word, folks, no matter how informal the dialogue is in your story. Just stick in that apostrophe.

Parentheses. This set of marks is not common in most modern fiction writing, but in non-fiction they’re used to insert a separate but related thought inside a sentence (see above paragraphs for other examples of this.) A multiple-sentence side note can get tedious if it’s all contained within parentheses. Exact rules probably depend on the writing style you might be trying to follow, or specific guidelines of a publication, but keeping a parenthetical statement to one sentence or a partial sentence is probably a safe bet.

Quotation marks. These marks are used to indicate dialogue, and to place “emphasis“ on certain words. The rule of italics versus quotes for emphasis probably varies by style guide or publication. In my experience, quotes around a non-dialogue word or phrase usually indicates something of a more light-hearted or sarcastic note rather than the more serious stressing of italics. Of course, when someone is speaking in a story, or you’re directly quoting someone else’s words in a text, begin and end the phrase with quotation marks. By the way, I’m referring to double quotes here. Single quotes (which can look like an apostrophe, but it’s not the same thing) is a whole different beast. Proper usage of single quotation marks again can vary depending on the style guide used, and also vary depending on whether you’re going by American standards or European standard.

Your writing deserves the best chance possible. Polish your punctuation so that your content can shine through!