Answer:
Suprasegmentals are important for marking all kinds of meanings, in particular speakers' attitudes or stances to what they are saying (or the person they are saying it to), and in marking out how one utterance relates to another (e.g. a continuation or a disjunction).
How does it help us?
Suprasegmental information is signaled in speech with variations in duration, pitch, and amplitude (loudness). Information like this helps the hearer segment the signal into words, and can even affect lexical searches directly."
