Suprasegmental features are prosodic elements of speech such as intonation, rhythm, stress and tone that operate over longer stretches of speech rather than individual sounds. They affect the pronunciation of segments and can change or clarify the meaning of words and sentences. Examples given include vowel length changing meaning in some languages, intonation conveying emotion, and stress and pausing altering sentence meaning in English. Tone languages also use pitch at the syllable level to distinguish word meanings.