 Assimilation is defined as a connected speech phenomenon where adjacent phonemes influence each other so that they become alike. There are two articulatory types. The first is referred to as assimilation of voicing, where two phonemes become alike in terms of voicing. An example is black art, where the voiceless vela plosive in black may become voiced under the influence of the initial vowel of art. In phenomena of place assimilation, two phonemes become alike in terms of their place of articulation. In the example in case, the alveolar nasal of in changes to a vela nasal under the influence of the initial vela plosive of case. Taking the direction of the phonemic influence, we can define assimilation as regressive backward directed, progressive or forward directed, or as coalescent. Regressive assimilation, as in ten coins or this shirt, typically occurs when a word final consonant, mostly an alveolar one, is assimilated to the first consonant of the next word. Progressive assimilation, as in rhythm or reckon, typically occurs in those contexts where a syllabic N follows a bilabial or vela plosive. In examples of coalescent assimilation, as in present-day English got you, which may become got you, two adjacent phonemes unite and fuse into one. In present-day English this process has occurred in many words historically and the pronunciation with a fused consonant is usually obligatory nowadays. Take a sure as an example. In present-day English assimilation is mainly optional and typically occurs in rapid conversation.