Those little dots often found in a sentence or quote are called an ellipsis. The term ellipsis comes from the Greek word meaning ‘omission,’ and that’s just what it does: an ellipsis shows that something has been left out. You can use an ellipsis when you’re quoting someone to show that you’ve omitted some of their words. For example:
“I wore my new silver, strapless, floor-length, silk dress and matching shoes.” could be shortened with an ellipsis to read: “I wore my new… dress and matching shoes.”
You can also use an ellipsis to show a pause in speech or the ‘trailing off’ of a sentence. You should only use the ellipsis this way in informal writing, however. For example:
“Andrew, can you, um… never mind, I forgot what I was saying.” “So, do you think we should…?”
How many dots are in an ellipsis? The answer is three, unless the omitted material includes the end of a sentence. You can think of that as a three-dot ellipsis plus the period at the end of the sentence.
For more tips on punctuation, read this blog post about using quotation marks.