Tone is the use of pitch in language to distinguish lexical or grammatical meaning – that is, to distinguish or to inflect words. All verbal languages use pitch to express emotional and other paralinguistic information and to convey emphasis, contrast and other such features in what is called intonation, but not all languages use tones to distinguish words or their inflections, analogously to consonants and vowels. Languages that have this feature are called tonal languages; the distinctive tone patterns of such a language are sometimes called tonemes, by analogy with phoneme. Tonal languages are common in East and Southeast Asia, Africa, the Americas and the Pacific.

Tonal languages are different from pitch-accent languages in that tonal languages can have each syllable with an independent tone whilst pitch-accent languages may have one syllable in a word or morpheme that is more prominent than the others.