In linguistics, intonation is variation in spoken pitch  

when used, not for distinguishing words as sememes (a concept known as tone), but, rather, for a range of other functions such as indicating the attitudes and emotions of the speaker, signalling the difference between statements and questions, and between different types of questions, focusing attention on important elements of the spoken message and also helping to regulate conversational interaction. 

(The term tone is used by some British writers in their descriptions of intonation but to refer to the pitch movement found on the nucleus or tonic syllable in an intonation unit.)  Although intonation is primarily a matter of #pitchvariation, it is important to be aware that functions attributed to intonation such as the expression of attitudes and emotions, or highlighting aspects of grammatical structure, almost always involve concomitant variation in other prosodic features. David Crystal for example says that "intonation is not a single system of contours and levels, but the product of the interaction of features from different prosodic systems – tone, 

#pitchrange, loudness, rhythmicality and tempo in particular."[1]  All vocal languages use pitch pragmatically in intonation—for instance for emphasis, to convey surprise or irony, or to pose a question. Tonal languages such as Chinese and Hausa use intonation in addition to using pitch for distinguishing words.[2] Many writers have attempted to produce a list of distinct functions of intonation. Perhaps the longest was that of W.R. Lee,[3] who proposed ten. J.C. Wells[4] and E. Couper-Kuhlen[5] both put forward six functions. weki