An ellipsis is a series of periods with a space before each and a space after the last. ( . . . )
In prose (MLA and APA):
Purpose: Used in a quote to omit material from the original sentence or sentences.
1. Use three periods when omitting part of a sentence.
"Medical thinking . . . stressed air as the communicator of disease, ignoring sanitation or visible carriers."
2. Use four periods when omitting material after a completed sentence or between two sentences (Note: there are no spaces before the first period or after the last in this case).
"Medical thinking, trapped in the theory of astral influences, stressed air as the communicator of disease. . . ."
3. If the author quoted uses ellipsis points, place brackets around your ellipses to distinguish them from those of the author.
"We live in California, my husband and I, Los Angeles. . . [. . .] I have never been here before."
In poetry (MLA):
In poetry, an ellipsis can be used to skip words, phrases, or even entire lines.
Omitting words or phrases: The ellipsis is used just as it is used in prose.
Omitting entire lines: The ellipsis consists of a line of three spaced periods.
In Worcester, Massachusetts,
I went with Aunt Consuelo
to keep her dentist's appointment
. . .
It was winter. It got dark