Are the cicadas deafening you this spring? Where we live they are out in force, causing people to talk. Some mention ‘si-KAH-da’, other say ‘si-KAY-da’. Why the difference, I wondered. And here, in an extract from the Boston Globe, is the explanation. It’s all about evolution, not of the species but of the English language.
In classical Latin, “cicada” was pronounced as “ki-KAH-da,” with hard c’s. The first “c” changed to a “ts” sound around the fifth century A.D., and the consonant further softened to “s” in Old French. When English speakers began importing Latin words, they looked to the French model, so words beginning with “ci-” like “circle,” “civil,” and “cicada” all took on the initial “s” sound.
But why would the second syllable of “cicada” be pronounced like “kay”? For that we can blame the Great Vowel Shift that marked the transition from Middle English to Modern English. Words with the stressed “a” sound, including borrowings from Latin, shifted from “ah” to “ay,” which you can hear in countless words like “table,” “radio,” and “stadium.”
For centuries, the “ay” pronunciation ruled for stressed “a” words regardless of their source. It even applied to words brought in from Spanish like “armada,” originally pronounced in English as “ar-MAY-da.” But eventually, “armada” fell prey to what the British phonetician John C. Wells calls “continental vowelism”: “Ar-MAH-da” displaced the older pronunciation because English speakers thought the “ah” sound was more appropriate for a Spanish import.
… By the turn of the 21st century, most British references gave “kah” as the primary variant, with “kay” still holding sway across the Atlantic.