The alveolar tap or flap is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents dental, alveolar, and postalveolar flaps is [?].
The terms tap and flap are usually used interchangeably. Peter Ladefoged proposed for a while that it may be useful to distinguish between them; however, his usage has been inconsistent and contradicted itself even between different editions of the same text. The last proposed distinction was that a tap strikes its point of contact directly, as a very brief stop, and a flap strikes the point of contact tangentially: "Flaps are most typically made by retracting the tongue tip behind the alveolar ridge and moving it forward so that it strikes the ridge in passing." This distinction between the alveolar tap and flap can be written in the IPA with tap [?] and flap [?] -- the 'retroflex' symbol used for the one that starts with the tongue tip curled back behind the alveolar ridge. This distinction is noticeable in the speech of some American English speakers in distinguishing the words "potty" (tap [?]), and "party" (flap [?]).
For linguists who make the distinction, the coronal tap is transcribed as [?], and the flap is transcribed as [?], which is not recognized by the IPA. Otherwise, alveolars and dentals are typically called taps and other articulations flaps. No language contrasts a tap and a flap at the same place of articulation.
This sound is often analyzed and thus interpreted by native English-speakers as an 'R-sound' in many foreign languages. In languages for which the segment is present but not phonemic, it is often an allophone of either an alveolar stop ([t], [d], or both) or a rhotic consonant (like the alveolar trill or the alveolar approximant).
When the alveolar tap is the only rhotic consonant in the language, it may be transcribed /r/ although that symbol technically represents the trill.
The voiced alveolar tapped fricative reported from some languages is actually a very brief voiced alveolar non-sibilant fricative.
|Voiced alveolar flap|
Features of the alveolar tap:
|Russian||?||'zealous'||Apical; palatalized. More common than a dental trill. It contrasts with a post-alveolar trill. See Russian phonology|
|Afrikaans||Standard||rooi||[?o:i?]||'red'||May be a trill [r] instead. See Afrikaans phonology|
|Arabic||Egyptian||||[?e?l]||'foot'||Contrasts with emphatic form. See Egyptian Arabic phonology|
|Assyrian Neo-Aramaic||[:]||'ground'||Used predominantly. /?/, however, is used in some dialects|
|Armenian||Eastern||?||'minute'||Contrasts with /r/ in all positions.|
|Basque||begiratu||[be'?i?a?tu]||'look'||Contrasts with /r/. See Basque phonology|
|Catalan||mira||['mi]||'look'||Contrasts with /r/. See Catalan phonology|
|Danish||Vil du med?||[?e? ?u 'me]||'Are you coming too?'||Possible realization of intervocalic /d/ when it occurs between two unstressed vowels. See Danish phonology|
|English||Cockney||better||['be]||'better'||Intervocalic allophone of /t/. In free variation with [? ~ t? ~ t?]. See Flapping|
|Australian||['be]||Intervocalic allophone of /t/, and also /d/ for some Australians. Used more often in Australia than in New Zealand. See Australian English phonology and Flapping|
|Dublin||Intervocalic allophone of /t/ and /d/, present in many dialects. In Local Dublin it can be [?] instead, unlike New and Mainstream. See English phonology and Flapping|
|Irish||three||[i:]||'three'||Conservative accents. Corresponds to [? ~ ? ~ ?] in other accents.|
|Scottish||Most speakers. Others use [? ~ r].|
|Older Received Pronunciation||Allophone of /?/|
|South African||Broad speakers. Can be [? ~ r] instead|
|Esperanto||esperanto||[espe'?anto]||'person who hopes'||Allophone of /r/. See Esperanto phonology|
|Greek||? / mirós||[mi'o?s]||'thigh'||Somewhat retracted. Most common realization of /r/. See Modern Greek phonology|
|Hindustani||?/?||[t]||'meaning'||See Hindustani phonology|
|Italian||caro||['ka?o]||'dear'||Allophone of /r/ in unstressed intervocalic syllables; may also occur in other unstressed syllables. See Italian phonology|
|Japanese||? / kokoro||'heart'||Apical. See Japanese phonology|
|Korean||/ yeoreum||[jm]||'summer'||Allophone of /l/ between vowels or between a vowel and an /h/|
|Limburgish||Hasselt dialect||weuren||['ø:n]||'(they) were'||Possible intervocalic allophone of /r/; may be uvular  instead.|
|Portuguese||prato||['p?atu]||'dish'||Dental to retroflex allophones, varying by dialect. Contrasts with /?/, with its guttural allophones and, in all positions, with its archaic form [r]. See Portuguese phonology|
|Scottish Gaelic||mòr||[mo:?]||'big'||Both the lenited and non-initial broad form of r. Often transcribed simply as /r/. The initial unlenited broad form is /r?/ (also transcribed as /?/ or /R/) while the slender form is // ([ð] in some dialects). See Scottish Gaelic phonology.|
|Slovene||amarant||[ama'?a:n?t?]||'amaranth'||Also described as trill [r], and variable between trill [r] and tap [?]. See Slovene phonology|
|Spanish||caro||'expensive'||Contrasts with /r/. See Spanish phonology|
|Tagalog||barya||[b'ja]||'coin'||Once allophones with /d/. May also be pronounced as a trill /r/ or an approximant /?/. See Tagalog phonology|
|Turkish||ara||['ä?ä]||'interval'||Intervocalic realization of /?/. See Turkish phonology|
|Yiddish||Standard||?||[bk]||'bridge'||Less commonly a trill [r]; can be uvular [ ~ ?] instead. See Yiddish phonology|
|German||Standard||Rübe||['?ÿ:b?]||'beet'||Varies between apical dental and apical alveolar; may be a trill instead. See Standard German phonology|
Features of the alveolar nasal flap:
|English||Estuary||twenty||'twenty'||Allophone of unstressed intervocalic /nt/ for some speakers. See English phonology,|
North American English regional phonology and Flapping