This document defines assimilation and provides examples of it occurring in speech. It discusses how assimilation is a phonological process where sounds become more similar when next to each other. Assimilation can be regressive, with the first sound changing to match the second, or progressive, with the second sound changing to match the first. It also describes different types of assimilation including place, manner, and voicing of sounds. Exercises are provided to have the reader practice identifying assimilation in words and sentences.