Assimilation has a very precise meaning when it’s related to studies of languages. Is a common phonological process bye which the phonetics of a speech segment becomes more like another segment in a word. In other words it’s when a letter (sound) is influenced by the letter (sound) before or after it so that it changes its sound and/or spelling. The word assimilation it self it’s said to be assimilated; it is derived from the latin prefix ad- meaning to and simil- meaning like but, instead of being adsimilated, it has the easier pronunciation of assimilated.
A common example of assimilation is “don’t be silly” where the /n/ and /t/ are assimilated to /m/ by the following /b/, in many accents the natural sound is “dombe silly”.
Assimilation can be synchronic being an active process in a language at a given point in time or diachronic being a historical sound change. There are 4 configurations found: the increase in phonetic similarity may be between adjacent segments or between segments separated by one or more intervening segments; the changes could be in reference to a preceding segment or a following one. Even when all four occur, it changes in regard to a following adjacent segment account for virtually all assimilatory changes. Assimilation to an adjacent segment are vastly more frequent than assimilation to a non-adjacent one.
If a sound changes with reference to a following segment, it is called “regressive assimilation”, the changes with reference to a preceding segment are called “progressive assimilation”. A lot of people find these terms very confusing because they seem to mean the opposite of the intended meaning. To avoid the problem exist a variety of alternative terms. “Regressive assimilation” is also known as right to left, leading or reciprocal assimilation. “Progressive assimilation” is known as left to right or preservative, lagging or lag assimilation.
Occasionally two sounds may influence one another in reciprocal assimilation. When such a change results in a single segment with some of the features of both components, it is known as coalescence or fusion.
1. / t / changes to / p / before / m / / b / or / p /
2. / d / changes to / b / before / m / / b / or / p /
3. / n / changes to / m / before / m / / b / or / p /
4. / t / changes to / k / before / k / or /g/
5. / d / changes to / g / before / k / or / g /
6. / n / changes to /ŋ/ before / k / or / g /
7. / s / changes to /ʃ/ before /ʃ/ or / j /
8. / z / changes to /ʒ/ before /ʃ/ or / j /
9. /θ/ changes to / s / before / s /