Learn English – Distinctive features of English diphthongs

Examples within a single morpheme exist (e.g., pIAno, & nAIve), and across morpheme boundaries, it would be very common (e.g., gOIng). These are not diphthongs because the two vowels occur in different syllables.

Certainly the i in words like bite and fright represents an /aɪ/ diphthong.

Phonemically, I come up with these:

1. /aɪ/ as in price, my, high, flight, mice
2. /aʊ/ as in mouth, now, trout
3. /eɪ/ as in face, date, day, they, grey, pain, reign
4. /ɔɪ/ as in choice, boy, hoist
5. /oʊ/ as in goat, toe, tow, soul, rope, cold
6. /juː/ as in cute, few, dew, ewe
7. /jə/ as in onion, union, million, scallion, scullion

Most examples are taken from here. What those all actually work out to phonetically varies a great deal across dialects and speakers. For example, many and perhaps even most North American speakers raise the /aɪ/ in tight to [ʌɪ], but not the one in died. You may wish to check out SoundComparisons.COM, where you can both see and hear the phonetic transcriptions for speakers of many, many different dialects, including words like four, hear, eight, cold, cow, fight.

You could also analyse words like way, yay, wow, yow as triphthongs if you really wanted to, although we don’t tend to do so in English. Instead they tend to have an initial /w/ or /j/ followed by a diphthong in normal notation. ^{_{(In Spanish though they’d be considered triphthongs, as in cambiáis, which has just two syllables, cam- and -biáis.)}}

Non-rhotic speakers claim to have others, but I have trouble thinking of those as diphthongs myself. I always analyse diphthongs as having a principal vowel to act as the syllabic nucleus and then a glide either before or after it. If the glide comes before the main vowel, as in /jə/, /juː/, it is a rising diphthong, and if the glide comes after the main vowel, as in /aɪ/, /eɪ/, /aʊ/, /oʊ/, /ɔɪ/, it is a falling diphthong. (Some people consider only the falling ones “real” diphthongs. I’m not sure why, since million has only two syllables for me, not three.)

I know of no diphthongs in English that have no glide in them, although whether you write your glides with /j/ and /w/ or as semivowels makes no great difference. This leads to alternate transcriptions, as in /eɪ/ for /ej/, and /aʊ/ for /aw/.

If there is no glide, I don’t count it as a diphthong. That means that I don’t read /ʊə/ as a single syllable. Rather, it has two syllables, as in the programming language named Lua /ˈlʊːə/. I guess I might write that /ˈlʊː.ə/ if I thought people might misunderstand me. And no, it is not homophonic with monosyllabic lure /ˈl(j)ʊːɹ/.

Non-rhotic speakers sometimes analyse words with words with ‹r› in them as diphthongs, where they substitute /ə/ for /ɹ/, but since that’s not a glide, it’s not going to make a new diphthong in my book; it might make a new syllable, though. Even though I say fire /faɪɹ/, I realize that they say /faɪ.ə/. For me that would then rhyme with the disyllabic maya /ˈmɑjɑ/, /ˈmaɪ.ə/, although it becomes challenging to assign the /j/ to one syllable or the other. I don’t see people writing fire /ˈfajəɹ/, but at least then it would seem like two syllables. But you end up reassigning the glide and changing the word from having an /aɪ/ diphthong in the first syllable to having a /jə/ syllable in the second.

For the record, here’s how I see the following r-bearing words:

• bearer /ˈbe(ɪ)ɹəɹ/
• tourer /ˈtʰʊɹəɹ/
• nearer /ˈniːɹəɹ/
• curer /ˈkʰjʊɹəɹ/
• layer /ˈleɪ.əɹ/, /ˈle.jəɹ/
• lair /leɪɹ/
• fiery /ˈfaɪɹi/ ^{_{(two syllables)}}, /ˈfa.jəɹi/ ^{_{(three syllables)}}
• fairy /ˈfeɪɹi/
• Faëry /ˈfe.jəɹi/ ^{_{(for trisyllabic rhymes in poetry)}}
• more /mo(ʊ)ɹ/, /mɔɹ/
• mower /ˈmoʊ.əɹ/, /ˈmowəɹ/

In that analysis, ‹r› is never part of a diphthong because /ɹ/ is not a glide, and if you write it as a schwa, you’ve likely introduced another second syllable. Non-rhotic AmE speakers (such as those from the South) always sound like they have have more syllables in their words to those of us from the North. The joke is there is no such thing as a one-syllable word in “Suthun”. For example, more is one syllable in the North’s /mo(ʊ)ɹ/, but two in the South’s /ˈmowə/.

Lastly, I realize that you can write ‹-er› as /ɚ/ or /ɹ̩/, as in murder written as either /ˈmərdər/ or /ˈmɝdɚ/. The problem is that we have only two rhotacized IPA symbols, stressed /ɝ/ and unstressed /ɚ/; for anything else that you want rhotacized, you have to use U+02DE MODIFIER LETTER RHOTIC HOOK, which doesn’t look so hot in most fonts, and doesn’t count as a combining character.