Compared to second language speakers who acquired the language later in life, heritage speakers often show native patterns in many areas of their grammar. Nevertheless, heritage speakers’ ultimate attainment in early adulthood is characterized by significant variability in their overall linguistic proficiency of the heritage language, which often falls outside the range of variation seen in monolingually-raised native speakers. Their native language abilities are dissociated by receptive and productive linguistic skills and within the language modules themselves. This chapter provide examples of the structural changes and differences commonly found in heritage language grammars, compared to the grammars of first-generation immigrants, who speak the same variety as the heritage speakers and who are the most comparable baseline. Heritage grammars are characterized by structural simplification, influence of the dominant language and slow and labored language processing during comprehension and production. Quantity and quality of input may drive processes of language change across generations. Although it has been suggested that changes observed in first-generation immigrants due to attrition are directly transmitted to heritage speakers it is argued that direct transmission from first to second generation is unlikely when considering the interaction of the intensity of the exposure and age of acquisition.

This chapter explores the relationship between language acquisition at the individual level and language change at the macro linguistic level. Given the semantic and pragmatic complexity of DOM cross-linguistically, the question arises as to how DOM is acquired by young children growing up in a monolingual environment. To what extent the semantic and pragmatic principles that guided diachronic developments constrain language development at the individual level? Language contact and bilingualism are often cited as critical factors in linguistic change at the macro-sociolinguistic level. Considering how DOM is acquired by different types of bilinguals and in different bilingual situations is critical to understand the link between language acquisition and language change. How language acquisition at the psycholinguistic level contributes to language change at the sociolinguistic and diachronic level, and the roles that both language internal (individual, cognitive factors) and language external (situational) factors play in the process and outcome of change are considered. Existing studies of DOM in L1 acquisition are discussed, followed by a critical review of studies in L2 and bilingual acquisition and in language change at the sociohistorical level. Monolingual children faithfully replicate the language they hear in the input while bilinguals are affected by dominant language transfer.

Nikolay Slavkov experienced learning the languages of the Soviet bloc in Bulgaria. Beyond the Iron Curtain of the Cold War, he developed a passion for English and immigrated to China and then to Canada. Initially reticent about plurilingualism and translanguaging, he slowly opened up to multilingual classes and his own plurilingual children to propose a reflection on the destigmatization of bilingual and multilingual practices.