 The southern shift affects the pronunciation of certain vowels within the southern states of the US. In most of these states, the triggering movement is a monotongueization of I with the result that words like hide or rise, some more like hard or rose. Furthermore, the onset of the mid-front vowel A is lowered and centralized to I so that slate sounds more like slide. Additionally, fronting as well as raising can be observed in other vowels. The southern shift may serve as a particular feature that helps to identify and differentiate the southern varieties of North American English from other varieties found in the northern and western United States.