Unstressed syllables are generally lower in pitch, quieter, shorter, and typically also phonetically reduced, notably with the vowels nearer to schwa.
[3] In English, such stress patterns carry relatively little functional load, especially in contrast to tone languages, such as Mandarin.
Nevertheless, correct positioning of stress is an important part of the language and greatly helps listeners to identify the words intended.
[4] In ongoing speech, the lexical stress patterns can be affected by the neighboring words and by syntactic and semantic structures.
For example, green house and greenhouse differ in that the second word loses stress in the latter, and generally this type of semantic combination exhibits this prosodic pattern.
The ultimate purposes of dialog – suggesting, persuading, building rapport, enjoying each other's company, comparing perspectives, making plans, and so on – are typically accomplished in part through the use of various prosodic patterns.
[9] For example, the prosody of "awww", when used as an exclamation of praise for a cute baby, involves creaky nasal voice, high pitch that is generally flat except with small initial and final peaks, relatively loud volume, and extended duration.