| Tom | has | been | there. | Has | he | though? | |
| tɔm | əz | bijn (bin) | ðeːə. | hæz | i | ðou? | |
| I | gave | her | a | book. | What, | to | her? |
| ai | geiv | ər | ə | buk. | wɔt, | tu | həː? |
Find as many words having strong and weak forms as you can by observing the ordinary speech of those around you. Then compare the list given in § 47.
For the dropping of h in the second part of compound words, see § 47.
36.
VOWELS
We have considered the sounds produced when the passage through which the breath passes is closed (stops) or narrowed (continuants); we now have to consider the sounds produced when the passage is wide enough for the breath to pass through without audibly brushing against the sides. These sounds are the vowels.
"Voice," produced by the vibration of the vocal chords, may be said to give body to the vowel; the shape of the passage through which the breath passes determines the features that distinguish one vowel from another, i.e. its quality. The shape of this passage is capable of almost infinite variation, which leads to a corresponding variety of resonances, and these determine the quality of the vowels.
Picture to yourself the inside of the mouth, and consider how the cavity may become larger or smaller, according as you separate or draw together the jaws; see what a difference it makes if you raise the tongue at the back, or in the middle, or in the front; bear in mind that the position of the lips may also modify the sound, as you will notice if, for instance, you utter as in who, first with the lips forming a long narrow slit, and again with the lips forming a very small circle (of the same size as the end of a lead pencil).
37. Of the well-defined vowels that which is articulated with least effort is [ɑ].[42] It is the earliest vowel sound uttered by the baby, before it has acquired control over the muscles of the tongue. It is also common as an interjection. Utter it, and watch the tongue with your mirror; you will see that the middle of the tongue ridge is slightly raised. The opening of the mouth is generally larger than in the case of the other vowels. See the diagram on p. [125].