[…] in English we must recognize, aside from the contours, two phonemic junctures: internal open juncture and external open juncture. The basis for this is as follows. There are many segments which we can assign to particular phonemes only by saying that whenever they occur a phonemic juncture is present: [a:y] is represented by /ay#/ as in tie, [k’V] by /k#V/ as in 'mark it', [pʰ] by /#p/ as in 'possess', etc. The one juncture /#/ serves as differentiating environment for all these segments in their respective phonemes. However, there are other segments than these, which we would wish to assign to the same phonemes: we cannot assign the [a˙y] of 'slyness' to /ay/ because it contrasts with the [ay] of 'minus', nor can we assign it to /ay#/ because it differs from the [a:y] of 'sly' which has been thus represented. We therefore set up a new phonemic juncture /-/ which occurs after morphemes within a word or phrase, and assign the segment sequence [a˙y] to the phonemic sequence /ay-/. The same new juncture serves as the differentiating environment which enables us to include other elements within one phoneme. These different junctures may also delimit the lengths of distinct contours. Thus the Swahili /#/ indicates the distribution of stress, but another juncture would be needed to indicate the distribution of intonations (e.g. question and assertion) in a long utterance where various of these intonations follow each other.
- Harris (1951), Pag. 86