How we change what others think, feel, believe and do
Or should I say what is emphasis? When you emphasis spoken words, the sound of the sentence changes. Typical characteristics of an emphasized spoken word include:
What this is doing is causing the emphasized word to be highlighted as particularly important, signaling to the other person that when they infer meaning from your sentence, they should take particular care with understanding the meaning you have given to this word.
Emphasis may also be created or increased by pausing just before the word or phrase to emphasize. This can be more subtle than heavy accentuation of the word itself.
Emphasis can also be added with body language, for example by nodding or tilting the body forward slightly in time with verbal emphasis.
Emphasis works by the contrast principle, where emphasizing something makes it different from the thing around it. Where it stimulates needs, such as with aggressive body language, it may use the arousal principle to get people stimulated.
Emphasis can also be caused by repetition, with subsequent repeats increasing the importance being signalled. Multiple repetition thus says 'this is very, very important.'
Emphasis causes attention
An emphasized word says 'Look at me! I am more important than the words around me. Pay attention to my meaning.' It makes the other person linger on that word as they search for the special meaning you have inferred.
If I say 'You are so good' it drags attention to the emphasized word 'good'. It can be as if you just said 'good'. The other person will linger longer here, taking more notice of the feelings that the word invokes and pondering more your intent in making this emphasis.
Using a pause before the word causes tension as the person wonders what will be said next. 'You are so...good'.
When emphasis grabs attention for one word, it automatically removes attention from other words, distracting the person from something which you want to slip in without them really noticing them too much.
If I say 'You are so good to help tidy the house' you may be so focused on the 'good' that before you realize it, you find that you have volunteered to help tidy up. If you do not help, then you are refuting the sentence, including the emphasized 'good' that feels so nice.
Emphasis implies a contrast
Emphasizing something often leads to it being contrasted with something else. Note how a simple change in emphasis changes the meaning of the line from the nursery rhyme 'Mary had a little lamb.'
You may well have spotted that emphasis invokes the opposite. Mary, not Tom. Little, not big. You can use this if you want to imply a contrast. 'It's warm today' invokes memories of cold days, making today seem even warmer. 'You are very kind' contrasts the other person with less kind people, setting up their identity as a generous person (and allowing you to ask something else of them).
Emphasis indicates arousal
When a person uses greater emphasis, more frequently, then this is a typical indication that they are emotionally aroused in some way. It may be a simple passion for the subject. It may also be anger -- other language and non-verbal signals will indicate which.