The goal of the research was to distinguish between types of language learners of Russian and to use that information to create a new perspective for instruction.
As research on heritage language learners' acquisition is relatively recent, dating back to the early 2000s, there remains much to be discovered about the process.
[11] In treating heritage language learning as interrupted L1 acquisition, in which the learner has access to Universal Grammar, it is expected that heritage language learners have knowledge of concepts found in early stages of L1 development, such as binding constraints, wh-movement, and aspects of lexical semantics, and struggle with grammatical concepts that require sustained exposure and practice in school-aged children, such as specialized vocabulary and uses of the subjunctive in Spanish.
[12][14] An incomplete grammar may be the result of attrition and fossilization of concepts in the L1 due to insufficient input once the child has switched to the dominant language.
[10] Fossilization occurs when a speaker lets go of non-core grammatical concepts but retains the basic core structure of the language.
[15] Pires and Rothaman use the expression, "missing-input competence divergence", to refer to instances when a grammatical property is missing from the colloquial variety.
The dramatic difference between standard and colloquial dialects is particularly evident in cases of verbal morphology, the clitic system, the subjunctive, and inflected infinitives in Brazilian Portuguese.
[15] Pires and Rothman (2009) found that Brazilian Portuguese heritage learners do not acquire inflected infinitives because their input does not "robustly instantiate these forms".
[13] In certain cases, heritage language learners receive their input from first-generation migrants who have shown effects of attrition in certain domains.
Consequently, the language learner would be missing grammatical properties in their input as a result of the interlocutor's attrition and would replicate these errors in their output.
[14] Pires and Rothman (2009) claim that due to their "inborn faculty of language", children automatically acquire the grammar found in their input.
Citing statistics found in studies on hearing children with deaf parents, Flores and Barbosa (2014) posit that bilingual heritage language learners need a minimum of 5 to 10 hours of interaction per week with the language to develop native-like proficiency.
Heritage language learning may help these children regain or avoid losing the ability to communicate with their parents.
[citation needed] Without the ability to communicate with parents or other family members, it becomes difficult to create an identity intertwined with one's heritage culture.
Those who lose the heritage language and choose not to actively maintain its use often assimilate into the dominant culture rather quickly.
Studies show that these individuals may have a confused sense of identity because they do not feel that they are fully accepted by either culture.
Their minority status means that they must navigate the effects of linguistic difference, and the expression of culture, ethnicity, and values through language.
[26] The language profile of a single immigrant community can also vary due to the presence of different dialects.
[26] Ebb and flow in a country's immigrant populations can also lead to significant variation in the abilities of heritage learners in a single classroom.
[27] A study conducted by the National Heritage Language Resource Center (UCLA) shows that in the United States, heritage speakers' interest in their home language tends to wane as they enter school, but may rise again in the later teenage years, prompting the decision to study it in college.
[26] The study and teaching of indigenous heritage languages stands at odds with colonial governments' earlier attempts at forced cultural assimilation.
[26] Formal education in heritage languages has existed since the nineteenth century, in immigrant communities and private and religious schools.
[3] Teaching heritage languages is not limited to the classroom; it may be a part of other local community contexts, such as a volunteer work and internships, field trips, oral history projects, or Scout troops.
The two types of students have different educational, cultural, and psychological backgrounds, which can lead to uneven learning outcomes if they are taught together.
Research by Yan and Elena (as cited in Yilmaz 2016) showed better performance in bilinguals as compared to monolinguals in metalinguistic ability, pragmatics, and attention control.
A combination of a social and practical limitation, classrooms may also discourage the use of minority languages by students during instruction.
[citation needed] In the sub-population of mixed-heritage learners, there may other stigmas that contribute to the loss of heritage language learning.
If it is not widely accepted to marry outside of their culture, and individuals decide to do so anyhow, they may lose contact with their ethnic community upon marriage.