Punctuation used to indicate a pause?

The punctuation used to indicate a pause is called ellipsis points or ellipses. Ellipses are three periods used at the end of a sentence or in the middle of a sentence, preferably with space around each period. Her is an example of the use of ellipses to indicate a pause in speech:

"I'm trying to remember what she said. It was something like . . . let's see . . . oh, now I remember!"

When there is an abrupt pause or interruption in dialogue, or when speech is suddenly broken off, then use an em dash:

"I won't be able to-"

"What? What do you mean, you won't be able to?"