Final answer:
The provided information does not include details about the research by Parodi & Guerrero on Salvadorian vocabulary knowledge among Mexican-Americans in Los Angeles; thus, no conclusion about language proficiency can be drawn. However, it is noted that issues of language, integration, and identity are complex and multifaceted within the Mexican-American communities in California.
Step-by-step explanation:
The research by Parodi & Guerrero is not described in the provided information, so it is not possible to answer specifically how knowledgeable first and second-generation Mexican-Americans in Los Angeles are regarding distinct Salvadorian vocabulary.
However, examining the complexities surrounding language, identity, and the experiences of Latin American communities in places like California can shed some light on broader issues of language proficiency and cultural integration.
It is often the case that subsequent generations of immigrants may experience a shift away from their ancestral language as they integrate into the dominant culture, with factors such as segregated schooling and language barriers playing a role in this process.
The history of immigration in California suggests that Mexican Americans and other Hispanic or Latino residents may hold varying views on immigration and policies because of differing personal experiences and socioeconomic status.
Furthermore, the linguistic diversity within Latin American communities in areas like Los Angeles is compounded by the various terminologies used to refer to oneself, indicating underlying complexities within identity and language use among Mexican-American communities.