sentences:  The unvoiced velar fricative sound is found in Scottish English, which distinguishes "loch" from "lock" .Accents like Cockney with ""h"-dropping" lack the glottal fricative , and dialects with "th"-stopping and "th"-fronting like African American Vernacular and Estuary English do not have the dental fricatives , but replace them with dental or alveolar stops or labiodental fricatives .Other changes affecting the phonology of local varieties are processes such as "yod"-dropping, "yod"-coalescence, and reduction of consonant clusters.