engthening, syllable structuring, and assimilation--even though these processes are not always strictly classified as phonological. They do, however, affect phonological, as well as linguistic, production as expected from EFL learners.
Assimilation is a process of connected speech in which one sound becomes similar to another, neighboring sound. Put in another way: It is a situation where "some phoneme is more nearly like its environment than is the phoneme sound in the base form" (Gleason, 1955, p. 83). "By 'more like' is meant: sharing more articulatory features" (Francis, 1958, p. 214). It is one of the most common types of morphonemic changes in the English language. For example, an alveolar consonant anticipates the place of articulation of a following sound, as in good boy, where the /d/ anticipates the labial articulation of /b/. When the process is complete, alveolar contact is lost altogether, and the /d/ can be said to have changed into /b/. The same process can be found in orthography, lexicology, and sociolinguistics.
Diachronic (historical) linguistics has paid particular attention to changes in the sound systems of languages. Certain common types of sound change, most notably assimilation and dissimilation, can be explained, at least partially, in terms of syntagmatic, or contextual, conditioning. For example, the word cupboard was presumably once pronounced, as the spelling indicates, with the consonant cluster pb in articulation (i.e. voicing was maintained throughout the cluster). Subsequently, the resultant double consonant bb was simplified. With a single b in the middle and an unstressed second syllable, the word cupboard, as it is pronounced nowadays, is no longer so evidently a compound of cup and board as its spelling still shows it to have been.
Partial and total assimilation of vowels in adjacent syllables constitutes a universal tendency of vowel interaction and is of relatively recent origin. Assimila...