Prosody is the study of speech's [[stress]], [[rhythm]], and [[intonation]]. These elements are called suprasegmentals because they are properties of speech units above the segments (vowels and consonants) such as [[syllable|syllables]] and larger units. It includes the pitch ([[fundamental frequency]]), loudness, and timing patterns that give the language its expressive qualities and help convey meaning beyond the words themselves. Prosody plays an important role in human communication by conveying emotions, attitudes, and emphasis. It helps listeners distinguish between different types of sentences and clauses. The speakers use fundamental frequency, energy, and duration variations to mark discourse structure like the distinction between a statement and a question. It is also used to emphasize a particular word or sentence. It can also be used to convey affective meanings such as happiness, surprise, sadness, or anger. A spoken sentence has a structure of [[prosodic unit|prosodic units]] that do not generally correspond to syntactic units such as phrases or clauses.