In ordinary conversational styles, ambisyllabic /t,d/ are realized either as [d] or [ɾ]. The first arises through t-voicing, and the second through /t,d/-flapping. A third possibility arises because of /t,d/-elision. As a result of these processes, the opposition between ambisyllabic /t – d/ tends to be lost, so that pairs like atom– Adam, parity – parody but also winter and winner tend to be homophonous.
t-Voicing will affect ambisyllabic /t/ after /n/ in certain words only. These words will vary from speaker to speaker, but common examples are seventy, certainty, carpenter. So pronounce these words /ˈsɛvn̩di/ etc.
Ambisyllabic /t/ may also be voiced to /d/ word-finally, as in the moment is, the treatment of. These /-nd/ clusters do not undergo flapping, and are treated like any such cluster in words that have –nd in the spelling, like sender (Rhodes 1992).
t/d-Elision occurs after /n/ in a strong syllable, as in center, fantasy, mental, and in phrases like went on, can’t afford, in front of.
Elision of /d/ is less common; it may occur in words like fundamental, indication, under, kinda (i.e. kind of) and in phrases like send it, stand up.
Verging on substandard are pronunciations like /ˈɪnərˈduːs, ˈhʌnərd, for introduce, hundred, where the switching around of /r/ and /ə/ creates the environment for the elision of /d/.
In words like atom – Adam, metal – medal, writer – rider both /t/ and /d/ are normally voiced and pronounced as a single tap of the tip of the tongue against the alveolar ridge. The articulation of flapped /t,d/, for which the symbol [ɾ] is used, is not unlike that of Spanish /r/ in pero, or Amsterdam Dutch /r/ in a word like serie. However, flapped /t,d/ do not have the friction that may be heard in the Dutch sound.
Flapping typically affects ambisyllabic /t,d/ after vowels. There may also be an /r/ before /t,d/. Recall that ambisyllabic consonants are created by WSP (I) or by liaison (II). Here are some examples. Pronounce them.
|hitting||kidding||hit Annette||read all of it|
|liter||shoddy||hit Anne||hid a treasure|
|bottle||heading||write a letter||made in Taiwan|
|Bottom||rider||quite at ease (2x)||ride a horse|
|Ghetto||avocado||meet a friend||he invited Ollie|
|Waiting||wading||bright eyes||a bad egg|
|hearty||hardy||start off||shored up|
Here are some questions you should be able to answer. Why don’t we get flapping in a tease, but do we get it in at ease?
And why don’t we get it in latex, but do we get it in later?
And why in my late ex?
Also recall that in words like button, cotton, mountain, where /t/ appears before syllabic /n/, we always get t-glottaling, even though /t/ is ambisyllabic.
As a result of flapping, the members of pairs like futile – feudal, writer–rider, liter – leader, metal – meddle, waiting – wading, latter – ladder are homophones.
In at least one context, however, Canadian English maintains a distinction. This is when /aɪ, aʊ/ precede /t,d/, as in writer–rider, right on! – ride on!, a lout in the house – allowed in the house. Before voiceless obstruents, Canadian English has centralized [ʌɪ, ʌʊ] (which causes about the house to sound somewhat like ‘abote the hoce’ or ‘aboot the hoos’). These allophones are also used before /t/ in a flapping context, so that writer – rider, for instance, are different, not because of the consonants, but because of the vowels: [ˈrʌɪɾər] – [ˈraɪɾər].