A recent question has reminded me of something I’ve been wondering about for a while: what is the correct way to pronounce tuple?
There are two possible pronunciations, one to rhyme with two pull (/tupəl/) and the other with supple (/tʌpəl/).
Take your pick. There will always be someone to agree with you... violently :)
tjʊp ə l, ˈtʌp ə l)
So, the actual pronunciation is actually either "tew-pel" or "tu-" as in "but".
Tuple can be pronounced as “tewple” ("toople”) or “tupple”
Broadly speaking, there are two main pronunciations of tuple: “tewple” and “tupple”. Neither one is incorrect, so there is no single correct way to pronounce this word. As Ed Guiness says in his answer, it is derived from the end of quintuple, sextuple, octuple etc. and the same variation exists in the pronunciation of these words.
“Tewple” usually starts the same way as “Tuesday”.
- /tjuːpəl/ “tyoople” in accents that maintain word-initial /tj/ clusters
- /tuːpəl/ “toople” in accents that drop /j/ after word-initial /t/. One commenter on this page, Marcin, has indicated that he uses and is used to hearing "toople" even in a British English context, and there is one upvote for his comment, but this is certainly not used by all British English speakers. It's unclear how widespread this pronunciation might be for otherwise non-/j/-dropping speakers.
- /tʃuːpəl/“chewple” in accents that change word-initial /tj/ to /tʃ/
“Tupple” = /tʌpəl/ in all mainstream accents of English.
“Tewple” is more regular, going from the spelling
The “tewple” pronunciation is more regular. (This doesn’t necessarily mean it is more correct, but some people might think it’s relevant.) In words of Latin origin, the letter “u” usually corresponds to the “long u” sound when it comes before a single consonant letter and a vowel letter, or before a consonant letter followed by “r” or “l” and then a vowel letter (e.g. nucleus, nutrient).
However, tuple = “tupple” is not an unprecedented sound-spelling correspondence
There are a small number of exceptions to this rule about the pronunciation of "u" before a single consonant followed by a vowel letter or the letter "r" or "l", so the pronunciation “tupple”, while less regular than “tewple”, does have some precedent.
For some words, an exceptional pronunciation with “short u” is only used by some speakers. Some of these pronunciations have been criticized by prescriptivists. (See the entry for “culinary” in “The Big Book of Beastly Mispronunciations”, by Charles Harrington Elster, who seems to view the pronunciation with /ʌ/ with a kind of resigned acceptance. The two other words I know of that are variable between “long u” and “short u” like this are jugular and truculent, although I haven't come across any prescriptive references that talk about them).
But there are other words like this where “short u” is the only possible vowel, rather than an optional variant. These mainly came into English through French (ducat, punish, public, publish, study) although there are also Latinate words taken from French that regularly have “long u” (such as soluble, voluble; the quality of the actual vowel in these words may be reduced to /ʊ/ or /ə/ since it's in an unstressed syllable, but the glide /j/ preceding the vowel makes it clear that it is underlyingly “long u”).
According to the Oxford English Dictionary, the word quintuple did come into English from French, so I see no clear etymological basis for considering it incorrect to pronounce it with either the vowel of “soluble” or of “public”.
“Tupple” is probably favored by analogy with single, double, triple
One important factor that has probably influenced the pronunciation of this word is analogy. The first British pronunciations given by the Oxford English Dictionary for quadruple, quintuple, sextuple actually have the stress on the first syllable. However, for American English it shows second-syllable stress. This probably developed by analogy with the stress pattern of the words single, double, triple, which all have penultimate stress. Another example of analogy among this set of words is the use of the -et suffix originally found in doublet (a word taken from French) to form triplet, quadruplet, quintuplet etc.
Single, double, triple all have short vowels, and this probably contributed to the use of a short vowel in quintuple etc. (I don’t know why the vowel of quadruple has apparently been immune to this influence.)
I was a little surprised to hear two people who sounded like Brits (Tim Isted and Dave Addey) both saying "tupple" in the "Introduction to Swift" session (402) at Apple's WWDC 2014. (Unfortunately, this is not public.) Like Colin Fine, above, I've always said /tjuple/, and thought that was standard in the UK. Then again, Tim and Dave work for Apple, so maybe they've adopted a company standard.
On "tjuple" vs. "toople": my guess is that this is the same UK vs. US variation as we see with "stew".
Here is a list of many online dictionaries out there that can help you with this. I suggest you click on the links and listen to the pronunciations yourself, when available.
noun [ C ] /ˈtuː.pl/ /ˈtjuːpəl/ /ˈtuːpəl/
Merriam Webster says
Origin and Etymology of -tuple
Now looking at one of them, say quintuple on the same dictionary, we get
\kwin-ˈtü-pəl, -ˈtyü-, -ˈtə-; ˈkwin-tə-\
The Free Dictionary: Lists two different pronunciations
ˈtjʊpəl , ˈtʌpəl
I prefer the first three dictionaries listed, naturally, and sometimes Collins. The first three consistently say that, pronunciationg of "tu" part of tuple is as in "stew" or "tool", but not rhyming with "but". More importantly, as said in Merriam-Webster, and also as did Ed Guiness in his answer, "tuple" should rhyme with its origins- quintuple, sextuple, etc.