, is opaque if one of the following surface structures exists: A common example is the interaction of the flapping of /t/ and the raising of /aɪ/ in Canadian English and other dialects.
Before voiceless consonants such as [t], the diphthong /aɪ/ is raised to sound more like [ʌɪ], so the word write is pronounced [rʌɪt].
In some contexts between vowels, /t/ is replaced by the (voiced) flap [ɾ], so (for example) patting is pronounced [pæɾɪŋ], similar to padding.
In words like writing, where /aɪ/ is followed by /t/ between vowels, both rules apply and the result is [rʌɪɾɪŋ]—with /aɪ/ raised to [ʌɪ] and /t/ flapped to [ɾ].
Due to this order of phonological rules, the interaction of the suffix vowel with rounding harmony is opaque.