The ellipsis (plural: ellipses) is a series of three full stops, used to show an omission in the text. In fiction writing, an ellipsis is often used to denote a pause (not an interruption – that’s something different), an unfinished thought, a trailing off, or to create a dramatic or ironic effect:
“I’m not sure if … what I meant to say was …”
The door closed slowly behind her …
“You are joking … aren’t you?”
Sentences that end in a question mark, or an exclamation mark, can be written with the ellipsis before or after:
“How did you … ?” or “How did you? …”
Technically speaking, there should be one full space before and after the three full stops, but when formatting a document from left-justified to fully justified, the characters are often padded out, leaving something like this:
Before: “Hello … how are you?” After: “Hello . . . how are you?
The latter can be distracting to the eye as it takes up a more space, and in my opinion, does not give a professional look, either on an e-reader or in printed form.
Fortunately, most word-processing programs recognise three full stops together as an ellipsis and can autocorrect them to signify one character. There may be an ellipsis already built in to the character set: in Microsoft Word, the ellipsis is obtained by pressing the keys: ctrl-alt-full stop. It inserts half a space before and after, and does not pad out when changing the justification of the text. Worth remembering.
One other thing: there are only ever three full stops in an ellipsis – in English, anyway – not four, five, or six, as I have seen! 🙂