A glottal stop is a speech sound you make by briefly closing your vocal folds to block airflow, then releasing it. You already produce this sound regularly, even if you’ve never heard the term. The catch in the middle of “uh-oh” is a glottal stop. So is the tiny pause you insert before a word that starts with a vowel when you want to emphasize it, like saying “I am NOT going” with a sharp, punchy start to “am.”
How Your Body Produces It
Your vocal folds (sometimes called vocal cords) are two small bands of tissue inside your larynx, or voice box. During normal breathing, they stay open to let air pass freely. During normal speech, they vibrate rapidly as air flows between them, producing voice. A glottal stop happens when you snap those folds completely shut, trapping the air below them for a split second, then release. The space between the vocal folds is called the glottis, which gives the sound its name.
You can feel this closure yourself. Hold your breath tightly, then release it into a vowel sound like “ah.” That moment of held breath, right before the vowel comes out, is your vocal folds pressing together. The release is the glottal stop in action. It’s essentially the same mechanism your body uses when you bear down or brace your core: the vocal folds lock shut to seal the airway.
Where It Shows Up in English
English speakers use glottal stops constantly without realizing it. The most obvious example is “uh-oh,” where the break between the two syllables is a full glottal closure, not just silence. But it goes well beyond that one expression.
At the start of phrases, most English speakers insert a glottal stop before words that begin with a vowel. When you say “I am” at the beginning of a sentence, especially with any emphasis, a glottal stop precedes the “I.” This is sometimes called “hard attack,” and it separates the vowel cleanly from whatever came before.
The most widespread use in everyday English, though, involves replacing the “t” sound. Say the word “button” at a natural conversational speed. Most American English speakers don’t actually touch their tongue to the roof of their mouth for that middle “t.” Instead, they close the glottis briefly: “buh-n.” The same thing happens with “kitten,” “mitten,” “bitten,” and “written.” In phonetic notation, “button” is transcribed as /bʌʔn/, with the symbol ʔ representing the glottal stop where the “t” would be. This pattern kicks in reliably when a “t” falls after a stressed syllable and before an “n.”
Younger American speakers, particularly in the Mid-Atlantic states, are extending this pattern further. “Manhattan” becomes something like “Man-ha-in” and “Clinton” sounds like “Cli-in,” with glottal stops replacing the “t” in each case.
Glottal Stops in British Dialects
If American English uses glottal stops selectively, certain British dialects have taken the process much further. Cockney English, the working-class dialect of London, is famous for replacing “t” with a glottal stop in a wide range of positions, turning “butter” into “bu’er” and “bottle” into “bo’le.” But it doesn’t stop at “t.” Cockney speakers also replace “p” and “k” with glottal closures in many positions, so a phrase like “put the bat in the back of the net” can lose nearly every final consonant to glottal stops.
This pattern has spread well beyond London. Estuary English, the dialect bridging Cockney and standard British pronunciation, carries many of these same glottal replacements. Scottish English also uses glottal stops heavily. Even in Received Pronunciation, the traditionally “standard” British accent, speakers insert a glottal stop before certain consonants at the ends of syllables: a subtle catch right before the final sound in words like “stop,” “that,” and “knock.”
When It Changes Word Meaning
In English, swapping a “t” for a glottal stop never changes a word’s meaning. You might sound more or less formal, more London or more rural, but “button” with a “t” and “button” with a glottal stop are still the same word. Linguists call this an allophonic relationship: the glottal stop is just a variant pronunciation of the “t” sound, appearing in predictable positions without affecting meaning.
Other languages treat glottal stops very differently. In Hawaiian, the glottal stop (represented by the ʻokina mark, which looks like a reversed apostrophe) is a full, meaning-carrying sound. The word written as “Hawaiʻi” includes a glottal stop between the two final vowels. In Hawaiian and Samoan, a word with a glottal stop and the same word without one can mean entirely different things. The pair /ʔika/ and /ika/ could refer to completely unrelated concepts, even though many non-native speakers wouldn’t hear the difference. Arabic has a similar situation: its first letter, hamza (ء), represents a glottal stop and distinguishes words from one another. In these languages, the glottal stop has phonemic status, functioning just like “b” or “k” or any other consonant that separates one word from another.
Its Symbol in Phonetic Writing
The International Phonetic Alphabet represents the glottal stop with the symbol ʔ, which resembles a question mark without the dot. You’ll see it in transcriptions like /həwaɪʔiː/ for “Hawaiʻi” or /mɪʔn/ for “mitten.” In informal writing, languages that use glottal stops phonemically often mark them with an apostrophe, as in “Hawai’i,” though this can cause confusion since apostrophes serve other purposes too.
What It Sounds Like on a Spectrogram
If you could visualize a glottal stop on a sound analysis display, you’d find it surprisingly hard to pin down. Unlike a “p” or “t,” which leave crisp, recognizable signatures, glottal stops show a variable cluster of acoustic features. Some look almost like a vowel, with continued vibration and smooth transitions from one vowel quality to the next. Others show irregular vocal fold pulsing or a brief stretch of creaky voice. Some tokens show a near-complete gap in the waveform, while others barely interrupt the signal at all. This variability is part of why the glottal stop can be so invisible to speakers who use it constantly: it blends into the surrounding sounds rather than standing out as a sharp, distinct event.
That acoustic subtlety helps explain why English speakers rarely notice they’re producing glottal stops dozens or hundreds of times a day. It’s a sound hiding in plain sight, fundamental to the rhythm of speech in ways that only become obvious once you know what to listen for.