How many sounds are there in English? (2): vowels

In an earlier post, I looked at how many consonant sounds there are in standard southern British English, generally known as Received Pronunciation RP). In this post, I will look at the vowels. As before, I will be looking at how many phonemes there are. The earlier post describes what a phoneme is. How many sounds are there in English? – Language Miscellany

Vowels of RP: a diagram

The following diagram displays the vowels of RP.

Notes on the chart:

1. The diagrams classify the vowels by position of the tongue vertically (high / mid / low) and horizontally (front / central / back).
2. The colon (:) after a symbol shows that this vowel is long.
3. Many phonologists identify two classes of vowel in English: tense and lax. The diagram captures this distinction by placing a grey border around the middle of the diagram to show lax vowels.
4. The vowels shown above as /e:/ and /o:/ are often pronounced as diphthongs (ɛɪ, əʊ), not as pure vowels. Thus, some phonologists do not treat them as separate phonemes and would not show them on the chart above.
5. When vowels are unstressed, they become less distinct from each other. For example, it may not be clear whether the short unstressed vowel at the end of happy is best shown as [i] or as [ɪ]. Similarly, is the first vowel in throughout best shown as [u] or as [ʊ]?
6. The positions depicted in the chart for a continuum, not discrete regions. Different phonologists would place some of the symbols in slightly different places on the chart.

Examples of the vowels

The following list gives, for each vowel on the chart, an example of a word containing that vowel.

Diphthongs

A diphthong is a a sequence of 2 (or occasionally more) vowels and/or semi-vowels. Here is a list of diphthongs in RP, with an example for each one. (as noted above, 2 of these diphthongs are common ways of pronouncing items appearing in the chart above).

Conclusion

Standard Southern British uses about 14 vowel phonemes, or 20 if the diphthongs are included. Together with the 24 consonants identified in my earlier post, that makes up 44 in total. 44 is a commonly cited total for the number of phonemes in this variety of English. (Different phonologists sometimes arrive at slightly different totals, both for consonants and vowels.)

Sources

The Phonology of English: A Prosodic Optimality-Theoretic Approach, Michael Hammond (1999)

Understanding English-German Contrasts, Ekkehard König and Volker Gast (2018)

English, Ekkehard König, in The Germanic Languages, edited by Ekkehard König and Johan van der Auwera

Phonology and Morphology, Roger Lass, in A History of the English Language, edited by Richard Hogg and David Denison (2006)

A Historical Phonology of English, Donka Minkova (2004)

British English: Received Pronunciation, Journal of the International Phonetic Association 34/2, Peter Roach (2004)

The Sounds of Language: An Introduction to Phonetics and Phonology, Elizabeth C. Zsiga (2013)

Handbook of the International Phonetic Association (1999)