An ellipsis [ … ] indicates material left out of a quotation.
Since readers will assume that all your quotations are short excerpts from longer sources, you do not need ellipses at the beginnings or ends of quotations.
When you omit material from a quoted sentence: skip a space, insert the ellipsis, skip a space, then resume the quotation.
Displaying his prodigious knowledge of English grammar, David Foster Wallace opines: “Hopefully at the beginning of a sentence … actually functions … as a ‘sentence adverb’ that indicates the speaker’s attitude about the state of affairs described by the sentence” (100-01).
And Hopefully at the beginning of a sentence, as a certain cheeky eighth-grader once pointed out to his everlasting social cost, actually functions not as a misplaced modal auxiliary or as a manner adverb like quickly or angrily but as a “sentence adverb” that indicates the speaker’s attitude about the state of affairs described by the sentence (examples of perfectly OK sentence adverbs are Clearly, Basically, Luckily), and only SNOOTs educated in the high-pedantic years up to 1960 blindly proscribe it or grade it down.
— Consider the Lobster and Other Essays
If the ellipsis coincides with the end of a quoted sentence: mark the end of the sentence with a period, skip a space, insert the ellipsis, skip a space, then start the next sentence.
Robert Kaplan draws a contrast between Nevill Chamberlain and Winston Churchill: “Chamberlain’s was a shallow realism. … But Churchill knew more” (18).
Chamberlain’s was a shallow realism. He knew his people wanted peace, and their money spent on domestic needs rather than on armaments, so he gave them these things. (When Chamberlain returned from Munich after appeasing Hitler, he was proclaimed a hero.) But Churchill knew more.
— Warrior Politics
If the ellipsis comes before the end of one sentence and the start of another: skip a space, insert the ellipsis, skip a space, insert the period, skip a space, then start the next sentence.
Andrew Sullivan points out that “of all our relationships, friendship is the most common … . In its universality, it even trumps family” (176).
For, of all our relationships, friendship is the most common and the most universal. In its universality, it even trumps family.
— Love Undetectable
Any good word processor can insert a true ellipsis mark, so approximating an ellipsis using periods and spaces is inelegant and unnecessary.
|Keyboard shortcuts for ellipsis mark [ … ]|
|Microsoft Word|| alt + control + period
alt + 0133
|Mac OS X||option + semicolon|
You can set up most word processors to automatically insert an ellipsis when you type three periods in a row, turning [ … ] or [ . . . ] into [ … ].