Intonation refers to variations in pitch when speaking, such as raising, lowering, or sustaining the voice at certain points. It is a part of supersegmental phonology and carries meaningful information. Speakers have control over pitch but some variations may occur unintentionally. Tone is the major pitch movement within a tone unit and contributes to meaning, along with prominence and the interaction between speaker and listener. English is not a tonal language but some others like Chinese are.