Does English really have triphthongs?

EDIT/TDLR: It appears that quite a few people have misunderstood this question. In a nutshell, it is asking why many sources, even scholarly ones, claim that the /aɪə/ sequence is a triphthong despite syllabic evidence to the contrary.

I am trying to discover whether words like pliers as pronounced in the south of England contain actual triphthongs, and the homophonic playas was chosen to illustrate the apparent paradox of what seem like a pair of identical two-syllable words where at least one is claimed to possess a triphthong in English.

To illustrate this, I chose two exact homophones by pairing the word playas with the typical southern English pronunciation of pliers, where a triphthong is alleged to occur. I first verified with native speakers of southern English that they indeed say these two words identically.

Note that by playa, I do not mean eye-dialect for the AAVE slang expression /ˈpleɪə/ (although that too would have worked for triphthong demonstrations). I instead mean the technical term playa used in geology and limnology, pronounced /ˈplaɪə/. Although playa derives from the Spanish word for beach, it does not (usually) mean that in English. The English word playa used here is a technical one having per the OED a primary sense of:

A flat silt- or sand-covered area, free of vegetation and usu. salty, that lies at the bottom of a desert basin and after rain becomes a temporary lake.

For example, the annual Burning Man festival famously takes place in a playa of the Black Rock Desert outside Reno, Nevada. The nonsense jingle was provided to make clear both the sense and the pronunciation of playa as discussed in the original post below.

¡Vamos a la playa!

Does the word playa have a triphthong in it, or two diphthongs, or what?

I’m thinking that playas and the RP pronunciation of pliers are homophones. Supposedly pliers has a triphthong in it there in RP. But since playas sounds the same as pliers, it must also have one, too.

That doesn’t seem right to me. If playas had a triphthong, it would have only one syllable, but my instincts tell me it has two. Which means that the RP pronunciation of pliers also needs to have two syllables and no triphthong, despite some sources saying otherwise.

The Question:

What’s going on here: is playas/pliers a one-syllable word with a triphthong, or is it a two-syllable word with something else in each syllable?

If playas/pliers contains a triphthong instead of two different syllables, that would seem to mean that this verse wouldn’t be rhyming trochaic tetrameter anymore then:

If you think you’d like to try a

        Frolic in the dusty playa,

Best to bring your own papaya,

        Sacred to the Sioux and Maya.

Furnace winds are quick to dry a

        Man who can’t himself deny a

Chug from flasks of Stolichnaya.

        Pack instead some jambalaya.

That doggerel wouldn’t have eight syllables per line anymore if playas and pliers are homophones with a triphthong and only a single syllable in them, since that would mean that you lose a syllable when try and a appear next to each other.

It doesn’t sound like that’s what’s happening to me. I don’t hear just one syllable there.

EDIT: I waited ten hours for other answers to appear, then presented my own findings. I do not pretend that mine is the only possible answer, and would like to hear what others have to say in their own answers.

The English word playa is pronounced /ˈplaɪ.ə/ in English with two syllables, with the dot there representing a syllabic boundary.

English doesn’t really have triphthongs because no phonemic sequence of three vowel sounds occupies the same syllable in English. As with a diphthong, all components of a triphthong must occur in the same syllable.

English phonetician John Wells, author of the Longman Pronunciation Dictionary, doesn’t believe that vowel sequences traditionally considered “triphthongs” like /aɪə/ actually are such. In his blog posting “John Wells’s phonetic blog: triphthongs anyone?”, he takes issue with the traditional British idea that those are actually triphthongs:

Some authors describe the English vowel system as including not only diphthongs but also triphthongs. Peter Roach (English Phonetics and Phonology,
4th ed., CUP 2009, p. 18-19) puts it like this:

The most complex English sounds of the vowel type are the triphthongs. They can be rather difficult to pronounce, and very difficult to recognise. A triphthong is a glide from one vowel to another and then to a third, all produced rapidly and without interruption.

He lists the triphthongs eɪə, aɪə, ɔɪə, əʊə, aʊə (later giving the example words layer, player; liar, fire; loyal, royal; lower, mower; power, hour) and continues [...] I find this account unsatisfactory. If the əʊə of slower is a “triphthong”, it is difficult to see any reason why the əʊɪ of going is not one too. If liar has a triphthong, surely trying must have one. [...] Similarly, I would argue that part of the definition of a true triphthong must be that it constitutes a single V unit, making with any associated consonants just a single syllable.

Given that, do we have triphthongs in English? I claim that generally, at the phonetic level, we don’t. I treat the items we are discussing as basically sequences of a strong vowel plus a weak vowel. (By ‘strong vowel’ I mean one that is stressable and the potential input to a weakening rule; by ‘weak vowel’ I mean one that is the potential output of a weakening rule. Diphthongs such as aɪ are included under the heading ‘strong vowel’.)

So according to Professor Wells, English doesn’t generally have triphthongs at the phonetic level, which he explains in more detail at the referenced article.

Therefore English playa has no triphthong at all, but rather two syllables where the stressed one has a ‘strong’ vowel — here a diphthong — and the second and unstressed syllable has a separate ‘weak vowel’ that is not part of the first syllable.

As Janus mentions in a comment, there may be English dialects in which certain phonemes have allophones that can produce a tautosyllabic triphthong. However, this is not phonemic, only phonetic, because there are no minimal pairs to prove an actual phonemic distinction.

As it is a Spanish word, Spanish phonetical rules should apply, and the semi-vowel, yot (j) would separate the "ai" dipthong from the final "a"

I speak Midlands American English (Upper East Tennessee, educated). Regarding English triphthongs two examples immediately occur to me: Gayle (a girls's name) and squirrel (the rodent).

RMH

'Pliers' and 'Playas' are not exact homophones by any stretch. Only the first half of the word (the posited first syllable) is the same. First of all the vowel sound of the posited second syllable in 'Pliers' is clearly a schwa (at least in an English accent) and the final consonant sound is the voiced /z/. In Spanish the second syllable would be pronounced "ass" as in with the more annunciated /æ/ vowel sound and the unvoiced /s/ at the end. So I don't see these as comparable at all. In "Playas", the third sound of the supposed triphthong is not a schwa so it's far more present in the pronunciation and it's therefore much more difficult to imagine this word as monosyllabic. No one would argue for the existence of the triphthong /aɪa/ I think. The case for the triphthong /aɪə/ is more sympathetic especially when considering words with no hard consonant ending e.g. admire. I'm not sure I would find myself arguing that "fire" is a two-syllable word in English. Essentially we are talking about the effect of the schwa to confuse the boundary between triphthongs and a 2-syllable distinction. Why strip it of that power? Source: English teacher, Spanish learner and speaker for 15 years, living in Mexico.

Is There a Hiatus in 'Hiatus'?
Certainly the words 'playas' and 'pliers' are three-vowel, bisyllabic speech items and should therefore not be classified as triphthongs. As they are homophones in GB English, we have to accept the phonological existence of the liaising consonant /j/ between the diphthong and the schwa in 'pliers', even though there is no graphical evidence for such a sound; so 'pliers' does not include a hiatus as it has an intervening consonant sound. Such intervening "phantom" sounds are also apparent: in the short 'I' sound in 'duke', in the 'I' and schwa sounds in the triphthongs in 'furor' (c.f. Fuehrer) and 'durian', and in different levels of the schwa preceding the 'l' consonant in 'eel', 'pal', 'pill' and 'bottle; the fleeting schwa in 'towel' might also create a triphthong.
In 'playas', the letter 'y' (a) acts as the second element of the 'ay' digraph indicating the 'ai' diphthong and (b) functions as a consonant melding agent between the diphthong and the final vowel sound. In words like 'myopic' and 'crying', the letter 'y' represents a diphthong and a melding agent. Phantom 'r', 'w' and 'y' consonants only provide intra-syllabic liaison. Letter 'r' and 'w' counterparts to the 'playas' - 'pliers' pair are 'flower' - 'flour' and 'snoring' - 'sawing'. If words such as 'playas' and 'pliers' are not triphthongs and include intervening consonants, what are these very common bi-syllabic speech units in which two or more vowel sounds and/or diphthongs are melded together into cohesive speech items? Here is a suggestion.

The 'playas' - 'pliers' pair is the tip of a phonological iceberg. There are several types of meld: "bi-phthongs" ('doing'), "vowel tri-phthongs" ('tiara'), "vowel-diphthong tri-phthongs" ('throughout'), "diphthong-vowel tri-phthongs" ('chaos'), "quadthongs" ('hiatus' and 'oasis'), and so on. The 'ea' combination is: a digraph in the vowel sounds in 'head' and 'seat', a "bigraph" (or syneresis) in the diphthongs 'area', 'theatre' and 'India', and a "bi-graph" in the melds in 'idea' and 'rhea'; the 'ui' digraph in 'fruit' has its bi-graph counterpart in the meld in 'fluid'), the 'our' trigraph in 'journey' and 'your' has its "trigraph" counterpart in the meld in 'sour', etc. The bigraph has two adjacent vowel letters sounded separately as a diphthong in one syllable, i.e., with no intervening consonant sound. The diphthong at the end of 'India' is seen fully merged as the monosyllabic vowel sound in 'dear', like the relationship between the diphthong in 'mayor' and the vowel sound in 'pear'.
By comparing 'area' with 'idea' (with different stressing) and the name 'Noel' with the festive 'noel' we can conclude that diphthongs and triphthongs are monosyllabic merged melds with no melding agents. In natural speech, melds like 'layer' and 'Leia' are often slurred to create triphthongs, like the Southern USA monosyllabic pronunciation of 'playas' and 'pliers' as drawled diphthongs.