Underline or italicize words which you want to emphasize. In printing and on many computers this may also be accomplished by bolder print.
The emphasis either is because of special information the writer to wants to call to the reader's attention or because the word or words are meant be stressed in speech.
Examples: He insists that two men saw him.
(Information the writer wants to call attention to)
You said what to Mr. Blank?
(Word meant to be stressed in speech)