The structure of the tone-unit

The structure of the English syllable was examined in some detail. Like the syllable, the tone unit has a fairly clearly defined internal structure, but the only component that has been mentioned so far is the tonic syllable. The first thing to be done is to make more precise the role of the tonic syllable in the tone-unit. Most tone-units are of a type that we call simple, and the sort that we call compound. Each simple tone-unit has one and only one tonic syllable; this means that the tonic syllable is an obligatory component of the tone-unit. (Compare the role of the vowel in the syllable.) We will now see what the other components may be.