Assimilation takes place when a sound changes its character in order to become more like a neighbouring sound.
Direction of Assimilation progressive reciprocal (double)
Degree of Completeness complete incomplete
Degree of Stability historical nonobligatory
Changes in the manner of articulation Loss of plosion plosive + plosive (e. g. lamp post) Nasal plosion plosive + /m, n/ (e. g. button) Lateral plosion plosive + /l/ (e. g. candle)
Assimilation affecting the place of articulation: Incomplete: 1. Labialization: sweet [swi: t]; twin [twin] 2. Alveolar → dental: breadth [bredθ] 3. Alveolar → post-alveolar: try [trai] 4. Alveolar → palato-alveolar (yod coalescence): should you [ʃʊd jə] → [ʃʊdʒə] tune [tju: n] →[tʃu: n] historical: patient, measure
5. Post-alveolar → alveolar: three [θri: ] 6. Bilabial → labio-dental: helpful [helpfəl] Complete: 7. Alveolar → bilabial: that pen [ðӕp pen]; ten men [tem men] 8. Alveolar → backlingual: ten cups [teη kʌps] good concert [gʊg konsət] 9. Alveolar → palato-alveolar: this judge [ðis ʤʌʤ] → [ðiʃ ʤʌʤ] this shop [ðis ʃop] → [ðiʃ ʃop]
Changes in the place of articulation 1. alveolar /t, d, n, l, s , z/ become dental when followed by /ð, θ/ 2. alveolar /t, d, / become post-alveolar before post-alveolar /r/ 3. /m, n/ become labio-dental before /f, v/
Voicing and devoicing 1. /m, n, l, w, r, j/ become partially devoiced after voiceless /s, p, t, k, f, ʃ, θ/ 2. voicing and devoicing of the possessive suffix – ’s/’s’, the plural suffix –(e)s and the third person singulat 3 voicing and devoicing of the suffix -ed