Structural changes in Spanish in the United States: Differential object marking in Spanish heritage speakers across generations

• Spanish heritage speakers were tested on knowledge of Differential Object Marking.
• Participants display omission of obligatory DOM with direct objects in written production.
• Participants made errors in a comprehension task testing DOM objects.
• Adult first generation immigrants display similar patterns as the heritage speakers.
• Structural changes with DOM are observed in first and second generation immigrants.

This study investigated changes with Differential Object Marking (DOM)—the overt morphological marking of animate direct objects—observed in Spanish heritage speakers who are second generation immigrants in the United States. Previous studies of these speakers found that they omit the obligatory use of a with animate, specific direct objects in oral production ( Montrul, 2004 and Montrul and Bowles, 2009). The present study assessed the potential effects of quantity and quality of input on the degree of DOM erosion by controlling for age of onset of bilingualism and by establishing whether this phenomenon would also be subject to attrition in the first generation of immigrants. A total of 64 young adult heritage speakers, 23 adult immigrants from Mexico, and 40 native speakers from Mexico matched in age and SES were tested with a written/auditory comprehension and a written production task. Main findings indicated that native speakers from Mexico performed largely at ceiling in both tasks, whereas the three immigrant groups, including the first generation immigrants, omitted obligatory a in written production and made errors in comprehension. These findings suggest that structural changes with DOM in US Spanish occur at the representational level in some individuals are due to both insufficient input in middle childhood and different parental input in adolescence and early adulthood, in addition to potential transfer from English.