Introducing English Linguistics

Miscellaneous processes.
Other processes occur in English as well:
Alveolar flapping 
In American English, the words writer and  rider can be homophones
because the alveolar plosives /t/ and /d/ can undergo a process known as
alveolar flapping, resulting in both words being pronounced as [ɹaiɾ].
For this process to apply, /t/ or /d/ must occur between vowels, and the pri-
mary stress needs to be placed on the syllable preceding /t/ or /d/. Both of
these conditions apply in writer and rider, as both /t/ and /d/ occur between
vowels, and the primary stress occurs on the syllables preceding both con-
sonants. Other words in which this process can apply include butter
[b ɾ], literature [liɾətʃ], and fatter [fæɾ].