Tones, Tonic Syllables and Tone Units

We saw in Sentence Stress and Tonic Syllables that sentences are made up of syllables and the syllables where the main pitch movement in the sentence occurs are called tonic syllables. The syllables that establish a pitch that stays constant up to the tonic syllable are called onset syllables. In the following example lives is the onset syllable, which is conventionally shown in capitals. LON is the tonic syllable, which is conventionally shown in capitals and underlined.

she LIVES in LONdon

We can also represent the intonation patterns in this sentence with an arrow: 

Notice that in this particular example the voice starts at a certain pitch, then goes up very slightly on the onset syllable and then stays level until the tonic syllable where the pitch falls noticeably. The pitch at which a speaker begins a sentence will depend on their own pronunciation habits, but will generally be higher than their normal habit if they are nervous or excited and lower if they are bored or very relaxed.

The pitch that is held from the onset syllable to the tonic syllable is known as the key. In the above example there is only one tonic syllable and we can say that the sentence is therefore composed of one tone unit. Tone units are conventionally noted by being enclosed within two pairs of slanted lines. So

a sentence consisting of one tone unit is shown like this:

//she LIVES in LONdon//

An sentence with two tonic syllables and therefore two tone units can be shown as: 

or, as:

//she’s LIVED in LONdon// SINCE she was TWENty//

Note that the tonic syllable is the last stressed syllable in a tone unit. A key feature of intonation is that we, as speakers, can use it to indicate to our listeners what we think is new information in a conversation and what is old, or already shared, information. Consider the following sentences where the intonation pattern is marked, as we have done up to now, with an arrow: 

The first example shows a question asking for new information. The second version shows a question asking for confirmation of something the speaker thinks he has already been told. The words are the same, yet the intonation patterns used show a contrast between the two versions. As we can see the
main movement of pitch is on the tonic syllable (in these examples, the syllable train). The main movements of pitch, within a tone unit, are called tones. In the first of the two questions above, the tone is described as a fall, and in the second as a fall-rise. These are shown in a commonly used notation system as ↘ and \↗ . In this system the arrows are placed at the beginning of the tone unit, but refer to the movement of pitch on or around the tonic syllable (the underlined syllable). It has to be said, however, that the movements of pitch (the tones) are not always tied precisely to the tonic syllable, they can start before and can finish after the tonic syllable.

Employing this system of notation the various sentences used in this section can be expressed as follows:

// ↘ she LIVES in LONdon//
//↘ she’s LIVED in LONdon//↘ SINCE she was TWENty//
//↘ WHAT time does your TRAIN leave//
//\↗ WHAT time does your TRAIN leave//

This quite complex notation system above can be a useful tool for learners in analysing intonation patterns particularly when they are taking notes or trying to learn vocabulary.