Tap and Flap
A tap and a flap are consonants formed by a single, rapid contact between two articulators, briefly interrupting the airstream. They are distinguished from plosives by the speed and minimal pressure of the closure: there is no build-up and explosive release, just a momentary touch.
Tap versus flap
The terms are often used interchangeably and many phoneticians treat them as a single category. Where a distinction is drawn, a tap involves the active articulator moving directly to the passive articulator and back along the same path, while a flap involves a tangential brushing motion — the tongue moves past the contact point rather than to it and back. The IPA provides distinct symbols for the alveolar tap [ɾ] and the retroflex flap [ɽ], but the alveolar segment in most descriptions is simply labelled tap-or-flap.
Distribution
The most familiar example to English learners is the alveolar tap [ɾ] of General American, which realises /t/ and /d/ between vowels when the second vowel is unstressed: city, butter, ladder, water. This process — sometimes called flapping or t/d-tapping — neutralises the /t/–/d/ contrast in that environment, making latter and ladder near-homophones. Australian English shows similar patterns; British Received Pronunciation does not. The tap [ɾ] is also the standard realisation of single intervocalic r in Spanish (pero), distinct from the trilled rr (perro).
Other tap and flap consonants
Languages elsewhere use taps at other places. Hindi and other South Asian languages contrast the retroflex flap [ɽ] with stops. Some West African languages have a labiodental flap [ⱱ], added to the IPA in 2005.
ELT implications
Vietnamese, Japanese, and Korean learners of English often substitute a tap for English /r/ — accurate enough in some positions but yielding hyper-foreign realisations elsewhere. Conversely, exposure to American flapping helps explain learner difficulty in distinguishing writing and riding in connected speech.
References
- Ladefoged, P., & Johnson, K. (2014). A Course in Phonetics (7th ed.). Cengage Learning.
- International Phonetic Association (1999). Handbook of the International Phonetic Association. Cambridge University Press.