There is little research on typical speech development in Vietnamese children and those learning English as a second language. Three key characteristics were found in monolingual Vietnamese children with reported speech impairments: substitution of less complex sounds, substitution of more complex sounds, and velar backing. However, some backing is seen typically in Cantonese development. Distinguishing disorder from difference requires considering patterns atypical to both languages and the primary language intelligibility rating. Cultural factors are also important when assessing Vietnamese families.