Ellipses (...) can be used to indicate that you’re trailing off before the end of a thought. Use them sparingly. Don’t use them for emphasis or drama, and don’t use them in titles or headers.
- “Where did all those donuts go?” Christy asked. Lain said, “I don't know...”
Ellipses, in brackets, can also be used to show that you're omitting words in a quote.
- “When in the Course of human events it becomes necessary for one people to dissolve the political bands which have connected them with another and to assume among the powers of the earth, [...] a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation.”