6.Conclusion

To conclude，it has been claimed that L1 skills，L2 aptitude，and L2 proficiency are related to one another（Sparks，Patton，Ganschow，& Humbach，2009），and thus strong support for linkages between students’ L1 skills and their L2 proficiency and achievement（i.e.，cross-linguistic transfer） has been emphasized and even advocated.For instance，Cummins's interdependence hypothesis（Cummins，1979，1984），as supported by a study conducted by Verhoeven（2007），maintains that L2 language and literacy are at least partially dependent on L1 literacy at the time of the exposure to the L2.This interdependence，at the same time，means that if bilingual children's L1 competence is low，their L2 competence is likely to be low as well.

Certainly，language use in the bilingual/multilingual family changes and evolves as the family grows（Barron-Hauwaert，2011）；for example，the transition from home to school may provoke a change in the children's and consequently the family's language use.Yet verbal skills，such as constructing and retelling coherent narratives，regardless of the L1 or L2，are more crucial than any for better communication with others.Furthermore，verbal skills serve as possible predictors of school success and disposition to literacy.The problem is the reality that children live in homes that support literacy development to differing degrees in both the L1 and L2（Snow，Burns，& Griffin，1998）.In addition to fostering L2 skills，in order to keep their mother tongue alive and active，parents are strongly encouraged to involve their children in a range of activities that nurture children's L1 skills.