Glottal Stop
The glottal stop, IPA [ʔ], is a voiceless plosive produced by complete closure of the vocal folds, which interrupts the airstream entirely before being released. Because the closure is at the glottis itself, no supralaryngeal articulator is involved.
Status across languages
The glottal stop is a contrastive phoneme in many languages — Arabic (the letter hamza), Hawaiian (the ʻokina, as in Hawaiʻi), Maltese, Tagalog, and several others — where it can distinguish word pairs. In English it is not phonemic but appears widely as an Allophone of /t/ and as a phonetic feature of certain vowel-initial syllables.
Glottal replacement and reinforcement of /t/
In many varieties of English, /t/ is realised as [ʔ] in specific positions. Glottal replacement is most common syllable-finally before a consonant or pause (bottle, button, get up), and is a defining feature of London English (Cockney) and Estuary English. Glottal reinforcement — a [ʔ] added before a /p, t, k, tʃ/ closure — is widespread even in Received Pronunciation and in General American before final voiceless plosives. Roach (2009) treats the glottal plosive as an alternative pronunciation of /p, t, k/ in restricted contexts rather than a separate English phoneme.
Other English contexts
A glottal stop may also appear before vowel-initial words spoken with emphasis (not Apples — Oranges) and at hiatus between vowels in careful speech (re-enter). In American English it is common in the negation contraction uh-uh [ˈʌʔʌ].
ELT implications
Learners from L1s without phonemic glottal stop often miss the t-glottalling pattern in fast English and may transcribe button with audible [t]. Conversely, learners whose L1 inserts glottal stops before all vowel-initial words (German, Vietnamese in some dialects) carry that pattern into English, blocking linking across word boundaries.
References
- Roach, P. (2009). English Phonetics and Phonology: A Practical Course (4th ed.). Cambridge University Press.
- Cruttenden, A. (2014). Gimson's Pronunciation of English (8th ed.). Routledge.
- Wells, J. C. (1982). Accents of English. Cambridge University Press.