The extraction of these contours from the segments of every utterance is particularly important because in many languages some of the contours will turn out later to constitute suprasegmental contour morphemes (intonation, etc.) which may occur elsewhere separately from the morphemes constituted by the segmental remnants. For example, if we extract the tone contour out of the segments of 'I’m going.' and 'He isn’t.' we get the tone sequence '020' for each; we can later identify this tone contour as a morpheme indicating assertion which occurs in both of these utterances.
- Harris (1951), Pag. 52