TYPES OF INTONATION
Before we embark on any discussion of the types of intonation, it is vital to note that the last content word in the sentence is usually the one that carries sentence stress. It is, therefore, the one that affects the intonation of the sentence. In fact, in its most technical sense, intonation refers to (a) categories of pitch 'peaks' and 'valleys' as well as their combinations at each sentence stress position (i.e., the last content word of the sentence), (b) types of pitch category concatenation, and (c) pitch of sentence fractions occurring before the first sentence stress.
All vowels with 'primary' or 'secondary' sentence stress, receive intonation features, which may be either 'valleys' (i.e., falls) or 'peaks' (i.e., rises). In the case of peaks, they may contain a unidirectional fall, or rise, again at the end resulting in either a rise-fall or fall-rise intonation pattern. Peaks are characterized by a quick rise confined to the vicinity of a sentence-stressed syllable. Peaks are of three types: early-peaks, medial peaks, and late peaks. When the rise precedes the onset of syllable stress, and is narrow in temporal extension, an 'early peak' will form. When the rise extends into the first half of the stressed syllable, it results in a medial peak. In the late peak, the rise starts after the stressed vowel onset and continues into the second half of the stressed syllable or beyond. Valleys, on the other hand, have a continuous rise, starting before the stressed syllable (early) or inside it (non-early) and extending as far as the beginning of the following sentence-stressed syllable. If there are several unstressed syllables between two sentence stresses a valley is thus realized as more gradual compared with the much quicker rise for a late peak. The less distance there is between stressed syllables the more difficult it becomes to distinguish between a "valley+peak" and a late "peak+peak" sequence.
Since it receives the most important stress of the sentence, the last content word of the sentence is considered to be the cradle of intonation. Therefore, the ups and downs of pitch in connection to this content word are often used to identify the intonation of a sentence. In general, English uses six different forms of intonation patterns: (a) falling, (b) rising, (c) falling-rising, (d) rising-falling, (e) take-off, and (f) level.
