A few illustrations of the importance of emphasis will be, perhaps, both agreeable and useful.
When a young lady says to a young gentleman, “You are a nice fellow; you are!”—she means one thing.
When a young gentleman, addressing one of his own sex, remarks, “You’re a nice fellow; you are;”—he means another thing.
“Your friend is a gentleman,” pronounced without any particular emphasis, is the simple assertion of a fact.
“Your friend is a gentleman,” with the emphasis on the words “friend” and “gentleman,” conveys an insinuation besides.
So simple a question as “Do you like pine-apple rum?” is susceptible of as many meanings as there are words in it; according to the position of the emphasis.
“Do you like pine-apple rum?” is as much as to say, “Do you, though, really like pine-apple rum?”
“Do you like pine-apple rum?” is tantamount to, “Can it be that a young gentleman (or lady) like you, can like pine-apple rum?”
“Do you like pine-apple rum?” means, “Is it possible that instead of disliking, you are fond of pine-apple rum?”
“Do you like pine-apple rum?” is an enquiry as to whether you like that kind of rum in particular.