Molecule is pronounced MOL-ih-kyool, with three syllables and the stress on the first one. The most common point of confusion is the ending, which sounds like “kyool” rather than “kyool-ee” or “mole.”
Breaking It Down Syllable by Syllable
The word has three distinct syllables: MOL-ih-kyool. Here’s how each one sounds:
- MOL (first syllable, stressed): Rhymes with “doll” in American English. In British English, it’s a shorter, rounder “o” sound, closer to “moll.” This syllable gets the emphasis.
- ih (second syllable, unstressed): A quick, soft “ih” sound, like the “i” in “kit.” It passes by fast because it carries no stress.
- kyool (third syllable, secondary stress): Sounds like the word “cool” with a “ky” at the front. Think of it as saying “cute” but replacing the “t” with an “l.”
Say it at natural speed and it flows as “MOLL-ih-kyool.” The middle syllable is so light it nearly disappears in casual speech.
American vs. British Pronunciation
The difference between American and British pronunciation is small and sits entirely in the first syllable. American speakers use a broad “ah” vowel (like the “a” in “father”), giving it the sound “MAHL-ih-kyool.” British speakers round that vowel slightly, producing something closer to “MOLL-ih-kyool,” with the “o” sound you’d hear in “hot” as spoken in southern England. The Cambridge Dictionary transcribes the American version as /ˈmɑː.lɪ.kjuːl/ and the British as /ˈmɒl.ɪ.kjuːl/. Both are correct, and both are universally understood.
Why the Ending Sounds Like “Kyool”
The unusual ending trips people up because English doesn’t have many words that end in “-cule.” The word comes from French “molécule,” which was itself borrowed from New Latin “molecula,” a diminutive of the Latin “moles” meaning “mass.” That Latin diminutive suffix “-cula” evolved through French into the “-cule” ending we have today, pronounced “kyool.” You’ll hear the same pattern in a handful of related scientific words: minuscule (MIN-ih-skyool), corpuscle (KOR-puh-sul), and opuscule (oh-PUS-kyool).
Common Mispronunciations to Avoid
The most frequent mistake is putting the stress on the wrong syllable, saying “moh-LEK-yool” as though it rhymes with “collection.” This likely comes from confusion with “molecular,” where the stress does shift to the second syllable (moh-LEK-yoo-lur). In “molecule” itself, the stress stays firmly on the first syllable.
Another common error is pronouncing it with two syllables, as “MOL-kyool,” skipping the middle vowel entirely. While the unstressed middle syllable is quick, it should still be audible as a brief “ih” sound. A third variant you’ll occasionally hear is “MOLE-kyool,” where the first syllable is drawn out to sound like the animal. Keep it short: “MOLL,” not “MOLE.”
A Quick Memory Trick
Think of the phrase “Molly’s cool.” Say it fast and you’re very close: Molly-cool becomes MOLL-ih-kyool. The rhythm matches almost perfectly, with the emphasis landing on “Molly” and “cool” getting a lighter push at the end.