Assimilation of voice: Only regressive assimilation of voice is found across word boundaries and then only of one type, since this matter is important for foreign learners, we will look at it in some detail.
If final consonant is a lenis consonant and initial consonant is a fortis. We often find that the lenis consonant has no voicing; this is not a very noticeable case of assimilation. Since the initial and final lenis consonants usually have little or no voicing anyway. When final consonant is a fortis and the initial consonant is a lenis, a context in which in many languages final consonant would become voiced, assimilation of voiced never takes place.
Examples: – I like that black dog [aɪ laɪk ðæt blæk dɔg ]
It is typical of many foreign learners of English that they allow regressive assimilation of voicing to change some consonants as follows:
– I like that black dog [aɪ laɪk ðæd blæg dɔg ]
This creates a very strong impression of a foreign accent and is something that should obviously be avoided. We have study about the assimilation at word boundaries. Now let’s look at assimilation at morpheme boundaries and to some extent also in morpheme.
If in a syllable-final consonant cluster a nasal consonant precedes a plosive or fricative in the same morpheme then the place of articulation of the nasal is always determined by the place of articulation on the other consonants thus : bump [ bʌmp ], tenth [ tenθ ], hunt [ hʌnt ], bank [ bæŋk ]
It could be said that this assimilation has become fixed as part phonological structure of English syllables since exception are almost non-existent. A similar example of a type of assimilation that has become fixed is the progressive assimilation of voice with the suffix [ s ] and [ z ] when a verb carries a third person singular [ – s ] suffix or a noun carries a [ – s ] possessive suffix, that suffix will be pronounced as [ s ] if the preceding consonant is voiceless ( fortis ) and [ z] is the preceding consonant is voiced.
Example:
– cats [ kæts ] ; jumps [dʒʌmps ] , works [ wɔːks ] ; dogs [ dɔgz ]
– runs [ rʌnz ] ; pats [ pæts ] ; pams [ pæmz]