As we have seen before, some of the world’s languages are tonal languages, in which using one tone instead of another one can cause a change in the dictionary meaning or in some cases even the grammatical categorization. English Language do not use tones in this way though tones are used for other purposes. Such languages are called intonation languages.
In previous posts we looked at five tones found in English one-syllable utterances but that is not the end of the story because when we look at continuous speech in English utterances we find that these tones can be identified only on a small number of particularly prominent syllables. So, for the purpose of analyzing intonation we can define tone-unit as a unit generally greater in size than the syllable is needed.
In its smallest form the tone-unit may consist of only one syllable so it would be wrong to say that it is always composed of more than one syllable. In order to better understand the concept, given examples are much better than a classic definition.
The examples are given in spelling form and no punctuation is used. The reason for not using punctuation in these examples is that intonation and stress are the vocal equivalent of punctuation, so that when these are transcribed it would be confusing to include punctuation as well.
One-syllable utterance: /you
Three-syllable utterance: is it /you
In the three-syllable utterance the third syllable is more prominent than the other two and carries a rising tone. The other two syllables are less prominent and are said on a level pitch. Since they are said on a level pitch, it would be unusual to describe them as carrying a level tone.
So, “is it /you” is an utterance of three syllables composed of one tone-unit; the only syllable that carries a tone is the third syllable. The syllable that carries a tone is called a tonic syllable. The tonic syllable not only carries a tone but also a type of stress that is called tonic stress.
Let’s extend our initial example to the following one:
\/John is it /you
You notice a fall-rise tone used with the word “John”; that is because when calling someone’s name it is very common to use such tone. There is no pause between “\/John” and “is it /you” in above example, so we may say that the four syllables make up a single utterance. Despite this fact, the utterance would normally be regarded as divided into two tone-units: “\/John” and “is it /you”.
We can conclude now that the tone-unit has a place in a range of phonological units that are in a hierarchical relationship: speech consist in a number of utterances; each utterance consist of one or more tone-units; each tone-unit consists of one or more feet; each foot consist of one or more syllables; each syllable consist of one or more phonemes.