1. Introduction

Bilingual or multilingual human resources are highly sought after due to the quickening globalization and internationalization of education processes. Based on the findings from Tucker’s [1] study, Feng and Wang [2] claimed that the number of bilingual or multilingual learners today all over the world is more than monolingual individuals, and many more children continue to be educated through a second language. In many countries, the acquisition of bilingual or multilingual proficiency is viewed favourably by policymakers, educators, and parents. The ideal outcome of bilingual education is the development of a broader enculturation, a more empathetic perspective of various cultures, and a deeper engagement with the cultures related to the language [3]. However, there still exist several issues that cannot be ignored in bilingual education. This paper explores the multifaceted challenges that educators and students face concerning these materials and presents viable solutions. The issues span cultural insensitivity, lack of authenticity, outdated content, limited language variety, inadequate exposure, and an uneven development of language proficiency. These problems impede students’ comprehension of cultural subtleties, hamper their ability to engage naturally in the language, and diminish the overall relevance of their learning experiences. The paper advocates for solutions that prioritize cultural sensitivity, authenticity, contemporary content, recognition of language diversity, and a balanced approach to language proficiency and exposure. Additionally, it underscores the significance of high-quality materials, accessibility, and teacher support in elevating the bilingual education experience.

2. Literature Reviews

2.1. Families-related Factors to Learner’s Bilingual Abilities

Parents’ attitudes toward bilingual education have a significant impact on their children’s language development. As Bartman [4] has stated, parental understanding, attitudes, and beliefs about the importance of bilingual education play a crucial role in their children’s language proficiency. Kabuto [5] has also proposed a similar idea, suggesting that parental choices influence children’s attitudes and beliefs regarding bilingualism, in the line with Bartman’s [4] notion. Parents with positive attitudes and beliefs think highly of their children’s bilingual teaching [5]. For example, parents who highly value bilingual education in China will send their children to early extra English lessons as soon as possible, some of them even take bilingual education into consideration while their children are not school-age. These children, exposed to second language learning early while acquiring their first language, tend to possess a better understanding of bilingual cultural knowledge and more experience in using a second language compared to children who only learn English as a compulsory subject at school [6].

On the contrary, parents with negative attitudes and a lack of understanding of bilingual education tend not to prioritize cultivating bilingual and biliterate abilities in their children [7]. For instance, in Ward’s [8] study, it was suggested that a majority of parents in England do not recognize the importance of language learning from an early age and often fail to provide encouragement and significance to foreign language acquisition for their children. This situation can be attributed to parents lacking a background in foreign languages and a genuine interest in bilingual education, although it may not be the norm. Bartram’s [4] findings support this idea, as he claimed that some parents without foreign language knowledge tend to hold more positive attitudes toward second language (L2) learning and highly value bilingual education for their children. In general, children’s language development is significantly influenced by parenting behaviors that exhibit positive traits. Specifically, families with positive attitudes toward their children’s bilingual education can enhance their bilingual abilities and achievements [5, 9].

In addition to the home language environment, home literacy instruction should also be considered. For instance, the presence of foreign language books on the bookshelf at home and the frequency of parents’ reading to their children play crucial roles in foreign language acquisition and children’s learning outcomes [5]. According to the findings of Raikes et al. [10], parent-child book reading yields certain benefits that contribute to children’s language learning. It not only expands their foreign language vocabulary but also nurtures their oral language skills. Similarly, in the study conducted by Farver et al. [11], they supported the findings proposed by Raikes et al. [10]. Farver et al. [11] discovered a positive correlation between the language used by parents and their children’s oral language proficiency in the language spoken by the parents. The more frequently parents engage in shared book reading with their children, the higher the level of oral language competence that children attain. In general, parents’ choices regarding language usage can either motivate or hinder their children’s language learning and development [5]

It is evident that the home environment, encompassing both the language spoken and literacy practices, exerts a significant influence on children’s bilingual abilities. As highlighted by Kabuto [5], families play a crucial role in what can be described as ‘invisible language planning,’ a concept distinct from visible language planning. This ‘invisible language planning,’ as elucidated by Leung and Uchikoshi [12] in their comprehensive study, refers to the intricate ways in which families shape their children’s language development. This includes the choice of languages spoken within the household and the selection of books for their children’s reading materials. The impact of this ‘invisible language planning’ is substantial. Studies, such as those conducted by Raikes et al. [10], have emphasized the positive effects of parent-child book reading, not only on vocabulary expansion but also on the cultivation of strong oral language skills in foreign languages. Similarly, Farver et al. [11] have corroborated these findings, underscoring the connection between parents’ language choices and their children’s oral language proficiency in the languages spoken at home. It becomes evident that the frequency of parent-child shared book reading, combined with deliberate language choices, significantly contributes to the level of oral language competence children attain. Moreover, Kabuto’s [5] research underscores the importance of a rich linguistic environment in the home. This environment encompasses both the presence of foreign language books on household bookshelves and the regularity of parental book reading. The availability of foreign language reading materials is essential for fostering language development. When children have access to a variety of foreign language books, it not only enhances their vocabulary but also promotes a deeper understanding of language structure and usage. In essence, the home language environment is a dynamic space where ‘invisible language planning’ takes place. It is within this context that families make choices that profoundly impact their children’s bilingual abilities. Encouraging the use of both the primary language (L1) and the target language (L2) within the home setting, coupled with the incorporation of foreign language books and consistent parent-child book reading, can significantly enhance children’s language proficiency. Therefore, understanding the vital role of the home environment in language development is pivotal for promoting bilingualism and nurturing linguistic competence in children.

2.2. Shortage of Qualified Bilingual Teachers

A professional bilingual teacher has to be equipped with abundant teacher knowledge and understanding of both languages, the effectiveness of teaching methods, and basic teaching skills used in bilingual education programs [13]. However, the number of bilingual teachers is fewer because of several reasons, such as they have not got effective training programs. In this part, the issues of bilingual teachers will be represented and the reasons for this fact are explained as well based on the kinds of literature I have reviewed. Additionally, the solutions to the problem can also be referred to at the end of this part.

Based on Mehisto [14], Banegas [15] noted in his study that the need for bilingual teachers’ knowledge or awareness is one issue that requires to be addressed in implementing content and language-integrated learning (CLIL). Specifically speaking, bilingual teachers are not professional to deal with the problems in the class, because they have got enough knowledge to carry out CLIL in the class. Apart from the low quality of bilingual teachers, the limited number of bilingual teachers is another issue to reform bilingual education programs [16]. Based on the study done by Pérez and Cañado [17] they claimed that lack of bilingual teachers is one of the most serious problems to go through with the bilingual program.

As Trapnell [18] said, most teachers pay less attention to improving their professional competence. There are two main reasons accounting for this. For one, bilingual teachers do not have enough time to attend professional training [16, 17]. Without abundant high-quality bilingual materials, as the writer mentioned before, in this situation, bilingual teachers need to make up their teaching materials and teaching plans for the class which exerts much burden on bilingual teachers’ working load [16]. To be more specific, as bilingual teachers, teaching bilingual learners are their main goal, however, as Amanti [16] mentioned that there are still many invisible works, which give them negative influence. For another reason, attending teaching training is not compulsory [17]. The majority of teachers do not take part in training programs as routine, some of them just ignore that.

Apart from that, the strict recruitment standards can also be seen as one of the reasons for the shortage of bilingual teachers [16]. Many applicants cannot meet the recruitment standard to be bilingual teachers, for these applicants, they have not got enough working experience to be competent for the post. Parents also express their high expectations of the quality of bilingual teachers [16]. For example, Chinese wealthy families are willing to send their children to Bilingual Schools with high tuition fees as early as possible, in that case, these parents set very strict standards for bilingual teachers so as to give their children the best education.

Based on the importance of bilingual teachers in bilingual education programs, the need for appropriate teacher training is particularly urgent [3, 19]. As Sánchez and Hernández [20] said, bilingual teachers can be given lessons in English if their English proficiency is B2 under the Common European Framework of Reference for Language (CEFR), they supposed that teachers need to have at least a C1 under CEFR. Breeze and Laborda [3] gave the same ideas in response to a previous study done by Sánchez and Hernández [20], Breeze and Laborda [3] claimed that teachers have to receive support so as to become more professional and fully competent in both languages, students’ first language and their target language, on both a social and an academic level. Bilingual teachers have to be equipped with abundant knowledge of the target language, because bilingual teachers need to adapt to teaching content courses, such as history, in a language that the students are not academically proficient and generally fluent [3]. Under this circumstance, the challenges for teachers are not only do they have high proficiency in the target language, but they need to gain enough knowledge of the course they teach. Additionally, it has to be compulsory for bilingual teachers to attend teaching training [18].

Apart from setting bilingual teacher programs to improve teachers’ profession, their salary needs to be increased to retain the remaining bilingual teachers and to attract more and more people to apply for this position as well [16]. Giving bilingual teachers some benefits such as extra emolument to motivate them to devote themselves to the job. For example, some international schools in Shanghai offer bilingual teachers the temporary apartments to help them deal with renting problem, which attracts more and more bilingual teachers [2].

3. Discussions and Critical Analysis

Bilingual education programs heavily rely on the quality and suitability of learning materials. These materials are essential for developing language skills in both primary and secondary languages [21, 22]. However, concerns persist regarding their adequacy. Based on reviewing literatures, several common issues of bilingual materials (i.e., the problems of cultural content, lack of authenticity, outdated content) are proposed as a result of students’ low bilingual proficiency. In this section, the writer will demonstrate each of these problems, investigate the problems and come up with the useful solutions to mitigate the influence of these issues.

3.1. The Problems of Bilingual Materials

One of the most pressing concerns within the realm of bilingual education programs centers on the discontent expressed by educators concerning the coursebooks employed in classrooms. This dissatisfaction predominantly emanates from apprehensions regarding the content featured in these bilingual coursebooks. Cooley [23] underscores that coursebooks crafted for less commonly spoken languages frequently exhibit a deficiency in essential cultural background knowledge and tend to offer insufficient explanations, thereby impeding students’ progress in acquiring proficiency in the target language. To exemplify this issue, Cooley’s research concentrated on dual-language programs attended by both English-speaking and Spanish-speaking students. The study illuminated how the substandard quality of Spanish learning materials had contributed to a widening gap in Spanish proficiency between these two student groups.

Another critical predicament revolves around the perceived inadequacy of bilingual learning materials. Durán-Martínez and Beltrán-Llavador [24] shed light on this issue and ascribe it to the prevalent practice of publishers translating and simplifying subject matter, often overlooking the nuances of methodology. This approach leads to the implementation of content and language-integrated learning (CLIL), which, regrettably, can have adverse effects on the efficacy of bilingual education. CLIL tends to disregard essential subtleties inherent in the process of language learning and teaching, ultimately leaving a discernible impact on students’ overall language proficiency.

3.2. The Results of Issues of Bilingual Material

The repercussions of these issues are diverse and profoundly affect bilingual education programs. The dearth of suitable, high-quality bilingual learning materials presents substantial barriers to achieving successful language acquisition. A study conducted by Siekmann et al. [25], focusing on indigenous languages, identified numerous challenges stemming from the scarcity of materials. These challenges encompass the inability to accurately represent ancestral knowledge and worldviews, the absence of linguistically appropriate resources tailored for elementary students, and a shortage of materials aligned with state-mandated content-area outcomes. These issues collectively create an environment in which effective language and cultural instruction becomes exceedingly arduous.

Furthermore, these challenges related to learning materials impose an additional burden on bilingual educators. They find themselves compelled to invest extra time and effort in crafting teaching materials due to the inadequacy of available resources [20, 26]. This supplementary responsibility not only impacts educators’ job satisfaction but also directly influences the quality of instruction provided to bilingual learners.

In summation, the predicaments associated with bilingual learning materials constitute substantial impediments to the triumph of bilingual education programs. These challenges encompass the absence of suitable content materials and the generally subpar quality of bilingual resources, resulting in a spectrum of adverse consequences for both educators and learners alike. It is imperative to address these issues diligently to ensure that bilingual education programs can effectively facilitate language proficiency and foster cultural understanding among students.

3.3. Solutions

To mitigate these challenges and improve the quality of bilingual learning materials, it is essential to establish specific criteria for selecting suitable materials. Drawing from Siekmann et al.’s [27] insights, these criteria include:

Language Authenticity: Materials should primarily be in the target learning language to provide learners with an authentic linguistic environment. However, for other subjects, both languages (L1 and L2) should be included to offer meaningful and cohesive language instruction; Cultural Relevance: Bilingual materials must convey cultural knowledge, recognizing its pivotal role in acquiring a second language. Cultural relevance not only enhances cultural understanding but also improves learners’ overall language efficacy; Grammar Integration: Materials should include target-specific grammatical patterns of the second language, recognizing that grammar is a fundamental aspect of language proficiency; Appropriateness for Learners: Editors and publishers must consider the characteristics of bilingual learners, including their age, cultural background, and target language proficiency level, to ensure that materials are appropriate and engaging; Illustrations: Familiar illustrations within materials create a comfortable and relatable learning environment for bilingual learners, fostering confidence and motivation in language acquisition.

These solutions aim to address the root causes of material-related challenges and enhance the overall learning experience for bilingual students. By adhering to these criteria, educators and policymakers can contribute to the improvement of bilingual education programs, ultimately leading to more successful language acquisition and cultural engagement among learners. In bilingual education programs, the choice and quality of learning materials play a pivotal role in determining the success of language acquisition and overall program effectiveness. These materials serve as the foundation upon which students build their linguistic skills and cultural understanding. However, it is crucial to address the persistent problems associated with these materials to ensure positive learning outcomes for bilingual learners [25].

4. Conclusion

Bilingual education is of paramount importance in our increasingly globalized world, where proficiency in multiple languages is an asset sought after by both individuals and society. This paper has extensively examined the multifaceted challenges that educators and students encounter in bilingual education materials and has provided insightful solutions to address these issues. One of the primary challenges highlights in this discussion is the inadequacy of bilingual materials, which encompasses concerns such as cultural insensitivity, lack of authenticity, and outdated content. These deficiencies hinder students’ ability to grasp cultural nuances, engage authentically with the language, and maintain relevance in their learning experiences. Furthermore, the shortage of qualified bilingual teachers compounds the problem, as they struggle to find suitable materials and create their teaching resources. Bilingual education should not only be about learning languages but also about embracing cultures, fostering empathy, and preparing individuals for a diverse and interconnected world as proposed by Siekmann et al. [27].

While this paper has addressed the complex challenges in bilingual education materials and proposed practical solutions, it is essential to acknowledge some limitations and consider future perspective in this domain. As Baker [28] claimed, the findings are too generalization. The challenges and solutions discussed may vary based on the specific context, language involved, and the age group of learners. A more nuanced understanding is needed for different bilingual education settings. Besides, implementing the proposed solutions may be constrained by resource limitations, particularly in underfunded educational systems, which could hinder their widespread adoption [28-30]. Based on current bilingual education situation, Stroud [31] claimed that future research should focus on developing innovative bilingual education materials that leverage technology, interactivity, and adaptive learning to cater to diverse learner needs. In the evolving landscape of bilingual education, these limitations should guide researchers and policymakers in shaping the future of materials and pedagogy to foster effective bilingual learning.