An ellipsis (plural ellipses) is a series of three periods, as you can see in the icon to the right.

As with most punctuation marks, there is some contention about its usage. The main point of contention is whether or not there should be a space between the periods (. . .) or not (…). MLA, APA, and Chicago, the most common style guides for students, support having spaces between the periods. Others you may encounter, such as in journalism, may not.

Quotes

Like the brackets we just learned about, you will primarily see ellipses used in quotes. They indicate a missing portion in a quote. Look at the following quote for an example:

Sauropod dinosaurs are the biggest animals to have ever walked on land. They are instantly recognized by their long, sweeping necks and whiplashed tails, and nearly always portrayed moving in herds, being stalked by hungry predators.

In recent years, a huge amount of taxonomic effort from scientists has vastly increased the number of known species of sauropod. What we now know is that in many areas we had two or more species co-existing alongside each other.

A question that arises from this, is how did we have animals that seem so similar, and with such high energy and dietary requirements, living alongside one another? Was there some sort of spinach-like super plant that gave them all Popeye-like physical boosts, or something more subtle?

It’s a lengthy quote, and it contains more information than you want to include. Here’s how to cut it down:

Sauropod dinosaurs are the biggest animals to have ever walked on land. They are instantly recognized by their long, sweeping necks and whiplashed tails. . . .

In recent years . . . [research has shown] that in many areas we had two or more species co-existing alongside each other.

A question that arises from this, is how did we have animals that seem so similar, and with such high energy and dietary requirements, living alongside one another?

In the block quote above, you can see that the first ellipsis appears to have four dots. (“They are instantly recognized by their long, sweeping necks and whiplashed tails. . . .”) However, this is just a period followed by an ellipsis. This is because ellipses do not remove punctuation marks when the original punctuation still is in use; they are instead used in conjunction with original punctuation. This is true for all punctuation marks, including periods, commas, semicolons, question marks, and exclamation points.

By looking at two sympatric species (those that lived together) from the fossil graveyards of the Late Jurassic of North America . . . , [David Button] tried to work out what the major dietary differences were between sauropod dinosaurs, based on their anatomy.

One of the best ways to check yourself is to take out the ellipsis. If the sentence or paragraph is still correctly punctuated, you’ve used the ellipsis correctly. (Just remember to put it back in!)

Pauses

The ellipsis can also indicate . . . a pause. This use is typically informal, and is only be used in casual correspondence (e.g., emails to friends, posts on social media, texting) or in literature. Because this use occurs in literature, you may find yourself quoting a passage that already has an ellipsis in it. For example, look at this passage spoken by Lady Bracknell, in The Importance of Being Ernest.

Well, I must say, Algernon, that I think it is high time that Mr. Bunbury made up his mind whether he was going to live or to die.  This shilly-shallying with the question is absurd.  Nor do I in any way approve of the modern sympathy with invalids.  I consider it morbid.  Illness of any kind is hardly a thing to be encouraged in others.  Health is the primary duty of life.  I am always telling that to your poor uncle, but he never seems to take much notice . . . as far as any improvement in his ailment goes.  I should be much obliged if you would ask Mr. Bunbury, from me, to be kind enough not to have a relapse on Saturday, for I rely on you to arrange my music for me.  It is my last reception, and one wants something that will encourage conversation, particularly at the end of the season when every one has practically said whatever they had to say, which, in most cases, was probably not much.

If you were to quote the passage, it may appear that something has been removed from the quote. So how can we indicate that this is not the case? If you think back to the bracket rules we just discussed, you may remember that [sic] can be used to show that an error was in the original. In a similar practice, we can enclose the ellipsis in brackets to show it appeared in the original work:

Well, I must say, Algernon, that I think it is high time that Mr. Bunbury made up his mind whether he was going to live or to die.  This shilly-shallying with the question is absurd.  Nor do I in any way approve of the modern sympathy with invalids.  I consider it morbid.  Illness of any kind is hardly a thing to be encouraged in others.  Health is the primary duty of life.  I am always telling that to your poor uncle, but he never seems to take much notice [. . .] as far as any improvement in his ailment goes.  I should be much obliged if you would ask Mr. Bunbury, from me, to be kind enough not to have a relapse on Saturday, for I rely on you to arrange my music for me.  It is my last reception, and one wants something that will encourage conversation, particularly at the end of the season when every one has practically said whatever they had to say, which, in most cases, was probably not much.