Final answer:
Differences between two dialects include variations in grammar, vocabulary, syntax, pronunciation, and expressions, with American dialects often categorized by rhotic versus non-rhotic accents. Standard American English is used formally, while nonstandard dialects reflect local culture and identity, with variability even within single cities.
Step-by-step explanation:
When discussing the differences between two dialects, we refer to variations in language specific to particular regions or social groups. These differences manifest in grammar, vocabulary, syntax, pronunciation, and common expressions. For example, American dialects can be categorized by their rhotic and non-rhotic accents, where rhotic speakers pronounce the '/r/' sound in words, and non-rhotic speakers do not. Additionally, some dialects add unique sounds or grammar constructions; for instance, in some areas, 'wash' becomes 'warsh' and 'alls' may be added to phrases.
A dialect is seen as either 'standard' or 'nonstandard' with Standard American English being used in formal situations and considered more academic. This is in contrast with nonstandard dialects, often associated with local color and cultural identity. The Midwest speaks with a Midland dialect, while the South features the Upland and Lowland Southern dialects. However, even within a single city such as New York, multiple distinct dialects may exist. Ethnicity can also influence dialect, as seen in the various speech patterns across the United States.