The Vowels of English (R.P.): There are twenty vowel sounds in the Received Pronunciation of England (R.P.). These include twelve pure vowels and eight dipthongs, belonging to different phonemes.
Detailed description of the Vowels of RP
During the articulation of this sound, the front of the tongue is raised in the direction of the hard palate, to an almost close position. The lips are spread, and thus it is a front close unrounded vowel.It is a long vowel. The different spellings for this vowel are e, ee, ea, ie, i, ey, eo as in the words eve, tree, heat, piece, receive, police, key and people respectively. It can occur initially as ineat, medially as in beat, and finally as in see. Some more examples: