The main research question we seek to answer in the present study is: "What effect does reduced input in the non-dominant and dispreferred language have on the acquisition of Russian gender morphology by a bilingual Turkish–Russian child: Is it still sufficient for its monolingual-like development or can it cause incomplete acquisition of Russian gender morphology, at least, in some domains?"

This study is a longitudinal case study.

The main source of data collection is video and audio recordings. Twenty-five recordings are available. They cover the period of between two years and 11 months (2;11) and 4;0. The data are examined in terms of the availability of masculine, feminine and neuter form-related genders, as well as availability of feminine and masculine semantic-related genders of nouns and pronouns in the first-, second- and third-person contexts. We look into whether the data of the bilingual child is marked with deviations from monolingual Russian data and/or incomplete acquisition of gender in any domain.

The findings of the present study, on the one hand, support the view that, by and large, reduced to a certain degree, input is still sufficient for monolingual-like language development; on the other hand, it demonstrates that reduced input may lead to non-monolingual-like and/or incomplete acquisition and, therefore, appears to be a main factor determining the development of a language and accounting for its strengths and weaknesses.