The morpho-phonemic processes with simple definitions and examples:
1) Assimilation
A sound becomes more like a neighboring sound in one or more features such as voicing, place, or manner of articulation.
Example: in- + possible → impossible. The /n/ changes to /m/ before the bilabial /p/.
2) Sandhi
A sound change that happens at a word boundary when words are pronounced together. It often involves linking, blending, or adjustment between neighboring words.
Example: in some English varieties, law and order may be pronounced with an extra linking sound, like lawr and order.
3) Dissimilation
One sound becomes less like another nearby sound, usually to avoid repetition or make pronunciation easier.
Example: library is often pronounced like li-bry in casual speech, where one /r/ is reduced or weakened to make the sounds less similar.
4) Haplology
A syllable or sound sequence is lost because two similar syllables occur next to each other.
Example: library is sometimes pronounced as libry. Another common textbook example is interestingly sometimes becoming intrestingly in rapid speech.
5) Metathesis
Two sounds switch position.
Example: ask pronounced as aks in some dialects. The /s/ and /k/ change order.
6) Addition
A sound is inserted into a word or form. This is also called epenthesis when a segment is added.
Example: athlete sometimes pronounced with an extra vowel sound, like ath-e-lete in careful or nonstandard speech.
7) Deletion
A sound is removed from a word. This is also called elision in many contexts.
Example: friendship may be spoken as frenship in fast speech, with /d/ deleted.
Simple comparison
Assimilation: sounds become more alike.
Dissimilation: sounds become less alike.
Haplology: one of two similar syllables is dropped.
Metathesis: sounds change order.
Addition: a sound is inserted.
Deletion: a sound is removed.
Sandhi: sound change at word boundaries.
