The falling tone of any level and range expresses certainty, completeness, and independence.
A rising tone expresses uncertainty, incompleteness or dependence.
A falling-rising tone may combine the falling tone's meaning of assertion, certainty with the rising tone's meaning of dependence, incompleteness. At the end of a phrase it often conveys a feeling of reservation, i.e. it asserts something and at the same time suggests that there is something else to be said.
Sentence Stress
is a special prominence given to one or more words according to their importance in the sentence. The main function of sentence stress is to single out the communicative centre of the sentence which introduces new information.
Types of sentence stress
Normal (syntactical) - is used to arrange words into sentences or intonation groups phonetically; it expresses the general idea of the sentence and indicates its communicative centre; it is related to rhythm.
Logical - special prominence is given to a new element in a sentence or an intonation group.
Emphatic – increases the effort of expression; both normal and logical stresses can be emphatic, it is the highest degree of logical and emotional prominence of words in a phrase.