english sound structure part 11. Bài tập luyện ngữ pháp tiếng anh cho mọi người, đây là tài liệu hay và hữu ích có thể giúp các bạn có thể nắm vững được các ngữ pháp tiếng anh cụ thể. | 128 Melody 9 simultaneously. These are processes which either spread or suppress a segment in its Note that the integrity of a melodic expression cannot be defined by î reference to the skeletal point to which it is attached. The fundamental motivation for the split between the skeletal and melodic dimensions militates against such a move. There is plenty of evidence to indicate that entire melodic expressions must be allowed to spread or delink quite independently of the skeletal tier. And there are many cases where the total suppression of melodic material evidently occurs without a concomitant loss of a position witness the phenomenon of compensât- ory lengthening discussed in . The latter process also exemplifies the poten- 1 tial for whole melodic expressions to spread into vacant slots. i Another subset of elements that can function as a class are those that code laryngeal . information to be discussed in the next section. The relevant contrasts associated with this dimension including tone in vowels and phonation-type in consonants are frequently accessed as a group and quite independently of other dimensions j On the other hand there exist many logically possible combinations of elements which simply never show such group behaviour. Take for example the non-occurring three-element subset composed of A h and R. Together these define a class that J includes non-high vowels coronals fricatives and plosives. No attested process t operates on all of these segment-types simultaneously. Other examples of unattested j three-element classes selected more or less at random include I N h N U @ A . . The challenge then is somehow to be able to pinpoint the small number of recurring element classes without also capturing the large number of non-occurring classes that an abandonment of the principle in 46 would imply. In autosegmental theory the response has been to modify the bottle-brush model of representations j In its place has evolved a .
