With the rise of globalization, English has developed numerous varieties in the communities it has entered and remained in. The native languages in these communities have also evolved due to prolonged interaction with English. This transformation goes beyond the surface manifestations and occurs in deeper levels, known as cultural conceptualizations. Thus, assessing cultural and social interactions within a linguistic landscape should consider not only the number of classified language groups but also the cultural conceptualization contacts evident in linguistic manifestations. Drawing from the cultural conceptualization systems encoded in American English and Vietnamese public signage, as generalized from previous studies, several key similarities and differences between the two speech communities are identified. These findings provide a criteria foundation for evaluating and classifying linguistic landscapes in Vietnam. Accordingly, public signage is categorized into four groups from a cultural conceptualization perspective: culturally native signage, culturally foreign signage, culturally hybrid signage, and culturally equivalent signage. Preliminary research results from the linguistic landscapes in Vietnam indicate an increasing presence of native English signage. Some English items also show signs of incorporating Vietnamese cultural conceptualizations, forming a variety known as Vietnamese English. Additionally, while Vietnamese public signage retains typical usage habits, it also integrates elements of the English cultural conceptualization system. The research findings and implications can significantly enhance the understanding, learning, and use of English and Vietnamese within Vietnam’s linguistic landscapes.