The dash is also used to indicate a sudden change or break in the thought; as,
1. When the millennium comes—if it ever does—all of our problems will be solved.
2. "I believe—" began the lawyer.
"Believe!" interrupted his client. "I don't want you to believe. I want you to know."
The dash is used before a word that summarizes the preceding part of the sentence; as,
He had robbed himself of the most precious thing a man can have in business—his friends.
After a comma the dash has the effect of lengthening the separation; as,
One thing the Puritans desired,—freedom to worship God.
Exercise 194—Parenthesis Marks ()