sandhi

Modification of the sound of a word or morpheme when juxtaposed with another, especially in fluent speech, as the modification of the pronunciation of don’t in don’t you from its pronunciation in isolation or in a phrase like don’t we.

A cover term for a wide variety of phonological processes that occur at morpheme or word boundaries, such as the fusion of sounds across word boundaries and the alteration of sounds due to neighboring sounds or due to the grammatical function of adjacent words.

the articulatory process whereby the pronunciation of a word or morpheme changes when it is followed immediately by another (especially in fluent speech)