Progressive assimilation: If a preceding sound is influencing a following sound, we call it progressive assimilation. Devoicing: A process by which voiced sounds become voiceless. Devoicing of voiced consonants often occurs in English when they are at the end of a word.
2.9.2 Phonological processes and phonological rules
The changes in assimilation, nasalization, dentalization, and velarization are all phonological processes in which a target or affected segment undergoes a structural change in certain environments or contexts. In each process the change is conditioned or triggered by a following sound or, in the case of progressive assimilation, a preceding sound. Consequently, we can say that any phonological process must have three aspects to it: a set of sounds to undergo the process; a set of sounds produced by the process; a set of situations in which the process applies.
We can represent the process by mans of an arrow: voiced fricative → voiceless / __________ voiceless. This is a phonological rule. The slash (/) specifies the environment in which the change takes place. The bar (called the focus bar) indicates the position of the target segment. So the rule reads: a voiced fricative is transformed into the corresponding