The Basics

[1] An ellipsis takes the place of omitted words in a quotation
    
             "
...and didn't even say goodbye."
             "She was talking about cooking, cleaning
...until she turned blue in the face."

Beyond the Basics

[2] Indicates a long thoughtful pause

             I wanted to tell her...no, needed to tell her.

[3] Indicates trailing off (as opposed to an abrupt interruption)

             I was so tired. I just couldn't do it anymore. Just couldn't
...

[4] Indicates a continuation of time

             The bomb counted down: ten, nine, eight...

[5] Indicates pauses in conversation as if a "realization" is occurring

             "But how could he...could she...could they?"

Syntax

Warning: different editors handle the ellipsis differently (three dot method vs. four dot), but for simplicity sake, I'll describe the "safe" method. Just
           be aware that other variations may be correct as well.

No spaces before or after the ellipses.

             "Don't let me fall
..."

No period after an ellipsis. (Doing so would be the four dot method.)

Do remember to close your quotation.

Although it is technically correct to have other punctuation beside an ellipses, in general writing (non-technical), it is best avoided.

Usage Key

Stylistically, it is helpful to think of ellipses points as a thoughtful sigh.

Misuse

The biggest misuse of ellipses is to overuse them. As with all highly stylistic constructions, a little goes a long way.

Remember: for an interrupted quote, us an em dash. Reserve ellipses points for long pauses, not abrupt interruptions.

Let's Talk Style

Stylistically, they are best used to give a thoughtful, contemplative feel to prose. Ellipses do not always have to be part of a quotation. They can be used for
unquoted thoughts as well.

              Man, I can't believe she dumped me
...me...on my birthday.

Let's see how the pros use it
Ellipsis (...)
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