The monophthong is a vowel in the production of which the organs of speech do not change their position throughout the whole duration of a vowel.
I. All English front vowels have the following features in common.
1. The bulk of the tongue is pushed forward.
2. Its front is raised in the direction of the hard palate.
3. The tongue-tip is placed at the lower teeth.
II. All the back vowels are characterized by the following common features.
1. The bulk of the tongue is pushed backward.
2. Its back is raised in the direction of the soft palate to different heights (high, mid, low).
3. The tongue-tip is drawn from the teeth /u:, O:/.
4. The lips are rounded, except for /A:/ and /V/.
III. The central vowels have the following features in common.
1. The front and the blade of the tongue are equally raised. They are neither pushed forward nor retracted, occupying an intermediate position.
2. The tongue-tip is at the lower teeth.
3. The lips are spread for /3:/ or neutral for /@/.
The diphthong is a monophonemic combination of two vowel elements with gliding articulation.
The stressed element of a diphthong (which is always the first one in English) is called the nucleus, the second one is called the glide.
There are eight diphthongs in English. According to the type of nucleus they fall into three groups:
- front diphthongs /I@, eI, e@, aI, aU/;
- central diphthong /@U/;
- back diphthongs /OI, U@/.
According to the type of glide they are grouped into:
- /I/ gliding diphthongs: /eI, aI, OI/;
- /@/ gliding diphthongs: /I@, e@, U@/;
- /U/ gliding diphthongs: /aU, @U/.
Note. The sequences /aI@/ and /aU@/ are biphonemic combination of a diphthong and the neutral /@/. The glide in them is very indistinct, e. g. In an °hour.|| The "Tower of °London.|| But the possessive pronoun ‘our’ is monophonemic, e. g. In our ° country.||
Date: 2015-01-02; view: 1353