Morphemes may have more than one variant in different environments, we can have another definition of morpheme, i.e. a morpheme is a group of allomorphs which have similar meaning or show semantic similarity, and are in complementary distribution. The change in form from the base into other allomorphs is called ‘morphophonemic’ change or alternation, while the study of morphophonemic change of morphemes in different environment is called, as mentioned before, ‘morphophonemic’.
Morphophonemic can be change, that is, change of the base of morphemes into the other allomorphs can be classified into the following types :
Assimilation is process by which a sound of a morpheme is made similar to that of another morphemes to which the former is added, for instance : "Assimilation is the influence of a sound on a neighboring sound so that the two become similar or the same. For example, the Latin prefix in- 'not, non-, un-' appears in English as il-, im-. and ir- in the words illegal, immoral, impossible (both m and p are bilabial consonants), and irresponsible as well as the unassimilated original form in- in indecent and incompetent. Although the assimilation of the n of in- to the following consonant in the preceding examples was inherited from Latin, English examples that would be considered native are also plentiful. In rapid speech native speakers of English tend to pronounce ten bucks as though it was written tembucks, and in anticipation of the voiceless s in son the final consonant of his in his son is not as fully voiced as the s in his daughter, where it clearly is [z]."
From the base of the Indonesian activating morpheme (men-) into /mǝm-/ (is called assimilation of point of articulation and the change /d/ into /t/ in a verb stem like /help/, which results in the new form /helpt/ form /help/ + /d/ is called assimilation of...