"Tom-ay-to"? "Tom-ah-to"? Let's not call the whole thing off!
In the world of great debates, there is one that has been long enduring and still keeps language prescriptivists awake at night: Is it "tom-ay-to" or "tom-ah-to"? Now, this may not seem as pressing as whether nuclear fusion is possible, but to people in the linguistic trenches, it is pretty darn close. After all, how many linguistic pronunciation ambiguities have been so long running and widely known that they have actually inspired a song?
So is it 'tom-ay-to' or 'tom-ah-to'?
To get to the bottom of the great tomato pronunciation debate, we have to go back —way past the Gershwins putting the ditty into the world.
'Tomato' was originally a Nahuatl word
According to linguist Jack Chambers, the fruit was brought over to Europe around 1500 by Spanish explorers who had developed a taste for it in the New World. According to the Oxford English Dictionary, the original name—"tomatl"—came from Nahuatl, an Uto-Aztecan language spoken in parts of Mexico and Central America. Once across the pond, the word was nativized as it begun to be used by speakers of European languages, meaning adapted to fit the sound system of the borrowing language.
Europeans turned the Nahuatl word into 'tom-ah-to'
In Spanish, the name for these little beauties was "tomate" (pronounced "tom-ah-te"), based on the sound system of Spanish, which, like most Romance languages, used a long "a" vowel (pronounced "ah") which was the closest vowel sound to the one heard in the original Nahuatl word. This pronunciation was then adopted by the British, who used a similar "ah" vowel (sort of like we hear in the British-sounding pronunciation of "father"). So, this foreign loan-word nativization process would seem to argue that "tom-ah-to" is the accurate loan-word form, at least outside of the real McCoy, "tomatl."
The Americans turned the British word into 'tom-ay-to' (but the British used that pronunciation too)
Well, it’s not quite so clear cut. American colonists, always a bit wayward, had also learned about and cultivated tomatoes but pronounced the word with a different vowel sound, the diphthongal [e] vowel (pronounced "ey" like in "hey"). According to socio-phonetician Charles Boberg’s work on foreign loan word nativization, this "ey" pronunciation was actually a common pronunciation assigned to many foreign loan words spelled with a similar vowel, like "potato," that had been borrowed into English prior to 1500—before the Great Vowel Shift changed things up so that new words with the "a" vowel took on either an "æ" sound (as in fat (or cat)) or an "ah" sound (as in "father").
The Great Vowel Shift was a series of changes that radically altered the pronunciation of the long vowels of English between the 15th and 17th centuries. Before the vowel shift, it turns out, such long "a" borrowings were typically pronounced "ey" (e.g. compare how we pronounce our nativized borrowings of ‘paste’ from the 14th century vs. ‘pasta’ from the 19th century).
Chambers suggests people adopted the ‘ey’ pronunciation of ‘tomato’ to match how the word ‘potato’ was already pronounced in North America—"tomato" replicated an existing pattern. And, in fact, the Oxford English Dictionary cites sources that suggest this vowel was one that was also found in British English at the time, but that was gradually replaced by the post-Great-Vowel-Shift "ah" pronunciation. So, "to-MAY-to" became the North American version of how to say the word “tomatl,” and, it appears, was at the time considered it a legitimate pronunciation.
The two countries later gravitated toward different pronunciations (maybe out of nationalism)
Of course, as we arrive in the 18th and 19th centuries, the North American accent sounded pretty awful to most Brits, even when it preserved older sounds. "Vulgar," in fact, was the way they often described it. In turn, particularly after the American Revolution, the emancipated colonies had little interest in sounding anything like their British counterparts. So, this early difference became something of a statement of Americanness in the face of British linguistic snootiness.
Canadian pronunciation tends to be more like the British pronunciation
But why do Americans still hear a bit more "tom-ah-to" across the border in Canada? Well, during and right after the Revolutionary War, thousands of British loyalists fled north to Canada. These refugees were more inclined toward the "tom-AH-to" pronunciation because many were showing allegiance to the motherland and the mother dialect.
The "tom-AH-to" pronunciation was further entrenched throughout the 19th century by the flood of Britains relocating to Canada for cheap land. But as Canada’s ties with Britain weakened over the course of the 20th century, more young Canadian speakers adopted the ‘tom-AY-to’ pronunciation—a linguistic nod to the growing influence of their friendly neighbors to the south.
You can still sometimes hear the 'British' pronunciation in New England
And what of New England, where you can still hear the "ah" pronunciation here and there (which also gives us eastern New Englander’s "vahz" instead of "vase")? Well, with port cities that continued ties to London via both family and trade, there too we see more extensive contact with "in vogue" 19th century British pronunciations than in other parts of the United States, so it's not surprising that the more British "to-MAH-to" would have had more cachet in New England and would have been more likely to survive in pockets to this day.
Either pronunciation is fine
And so the hold-outs in the great "tom-AH-to"/"tom-AY-to" debate we still find scattered around the United States today are either those few who were already "tom-Ah-to" speakers before everyone shifted toward the North American pronunciation and who passed it down to their children, or simply those who feel that sounding British is the bomb. But, no matter what your feelings are about which is more correct, they still taste great on sandwiches, so I say call them what you will.
Image courtesy of Shutterstock.