THE BROADER CONTEXT Global demographic trends, including voluntary immigration, the arrival of refugees, and a range of policies concerning bilingual education, mean that teaching students in a language that is different from the home language (L2) is far from being an aberration. In some contexts, most or all students in the classroom speak the home language (e.g., Spanish in the case of Latino/a children in certain areas of the United States; English in the case of students in French immersion programs in certain Canadian regions). In other contexts, the language of instruction may be the societal language, but an array of languages are spoken at home (e.g., Turkish, Moroccan, or Surinamese in the case of immigrants to the Netherlands; Urdu, Mandarin, Arabic, Persian, Spanish, or Portuguese in the case of typical classrooms in metropolitan cities such as Toronto, New York City, London, or Melbourne; Arabic, Polish, Turkish, and Spanish in the case of typical classrooms in Paris). Geopolitical and historical circumstances mean that multilingualism in its many forms is prevalent and that it has different faces around the globe. Reports from international bodies such as the Organization for Economic Cooperation and Development (OECD, 2010) and the United Nations Educational, Scientific and Cultural Organization (UNESCO, 2005) indicate that the proportion of immigrants and refugees around the world whose children need to develop their language and literacy skills in a societal language that is different from their home language is on the rise. There is evidence that these L2 learners are at an increased risk of experiencing academic difficulties (OECD, 2010), but this risk is mediated by various contextual factors. Some L2 students struggle to achieve academically because they need to gain proficiency in the school language, and we know that it takes time to achieve adequate proficiency in the L2 (Farnia & Geva, 2011; OECD, 2010; see Lervåg & Aukrust, 2010 for a meta-analysis). Contextual factors such as home literacy levels, inadequate language and reading instruction, poverty, and systemic discrimination also cannot be ignored (Geva & Wiener, 2015; Leseman & de Jong, 1998; Snow & Dickinson, 1990; Karlsen, Geva, & Lyster, 2016). A FOCUS ON L2 STUDENTS WITH LEARNING DIFFICULTIES Notwithstanding the contribution of such broad contextual factors that may affect academic achievement, some L2 students may also have learning difficulties such as dyslexia or language impairment. Such difficulties are associated with poor academic achievement and require intervention and accommodation. However, in the field of learning disabilities (LDs), one finds evidence for both over- and underidentification of learning difficulties among L2 students (Geva & Wiener, 2015). The question of how to identify L2 students who have an LD reliably has been controversial and challenging due to factors related to overidentification of some students in their L2 as having an LD (e.g., Cummins, 1984; Solari, Petscher, & Folsom, 2012) and underidentification of other students learning L2 who actually have LD (e.g., Limbos & Geva, 2001). In recent years, a growing number of developmental researchers have addressed the L2/LD conundrum. Findings from longitudinal developmental research have refined scientific understanding of how components of L2 language and literacy develop over time in typical and atypical L2 students, as well as understanding of the cognitive processes that underlie LD, the role that L2 proficiency plays in the development of these components, and the affinity between L1 and L2 skills. The confluence of these broader contextual factors with developmental research of L2 learners who may have LD provided the impetus for this special issue. This issue brings together five articles that focus on L2 students with learning difficulties. The articles are situated in one way or another in longitudinal research and address the development of language and literacy skills in L2 students who have learning difficulties involving decoding, and language and/or reading comprehension. The articles are diverse in terms of the nature of the L1 and L2 of the students, and they vary considerably in their methodology. Nevertheless, key theoretical issues that tie together this diverse group of studies include questions such as the following: Are the language, reading, or cognitive profiles of L2 students with LD stable over time? Are the language, reading, and cognitive profiles of L2 students with LD stable across their L1 and L2? Is it possible to predict/identify a learning difficulty early in L2 learners? What skills should be targeted in the assessment of L2 students who may have LD? In the next section, we provide an overview of how the five articles forming this special issue addressed these questions. OVERVIEW OF THE STUDIES Swanson's (2017) article is based on the analysis of language, reading, and cognitive data available for a large sample (N = 450) of English learners who were recruited in Grades 1, 2, or 3. The home language of all students was Spanish. Students were administered a large battery of cognitive, vocabulary, and reading measure in both Spanish and English once a year for 3 consecutive years. Latent transition analysis identified three latent classes: typical readers, students with reading disabilities, and students with late emerging reading disabilities. Findings indicated that the cognitive, language, and reading profiles of the first two groups remained stable across testing waves. Early language and reading profiles of the latent class representing late emerging reading disabilities were similar to those of typical readers. What distinguished these two latent classes were early signs of inattentive behaviors that were associated with a late emerging reading disabilities latent class. Swanson's study demonstrates that inclusion of cognitive measures such as working memory, short-term memory, and processing speed in the L1 and the L2 enabled a more accurate identification of latent class profiles. This underscores the importance of including cognitive measures in the L1 and L2 in the assessment process. Chung, Koh, Deacon, and Chen (2017) used a growth curve analysis approach to investigate predictors of word reading in English and French in a group of 69 Canadian students who attended a French immersion program. They tracked cognitive, language, and reading skills of children from Grade 1 to Grade 3. Chung et al. asked whether it would be possible to predict growth and Grade 3 word reading outcomes in English and French on the basis of Grade 1 performance on phonological awareness, orthographic processing, and vocabulary skills in English and French, respectively. In line with other research, Chung et al. found that English and French vocabulary skills did not predict word reading skills in English and French, respectively. However, the growth curve analyses indicated that English phonological awareness and orthographic processing, assessed in Grade 1, predicted English word reading in Grade 3. Findings also indicated that Grade 1 French phonological awareness and orthographic processing predicted French word reading in Grade 3. In addition, English orthographic processing predicted the rate of growth in English word reading. In a nod to the consistency question, Chung et al. report that a subgroup (n = 6) identified in Grade 1 as poor decoders generally fell behind their typically developing peers in both English and French across all measures in all three assessment waves. The article by Verhoeven, Steenge, van Leeuwe, and van Balkom (2017) focused on factor structure in the language of 140 bilingual children coming from three home language backgrounds (Turkish, Moroccan, or Surinamese) in the Netherlands. These children were identified as having a specific language impairment (SLI) in Dutch (their L2). This article addresses the question of whether the classification of language components that underlie SLI in monolingual children is also applicable when one examines bilingual children. To that end, this team used tasks that are typically used to assess four language components among monolinguals with SLI, namely, speech production/phonological memory, auditory perception/phonological conceptualization, lexical-semantic, and morphosyntax. A “pseudo” longitudinal approach was undertaken that used both cross-sectional and longitudinal data. The sample consisted of three combined age groups (6–7, 8–9, and 10–11 years). The analysis focused on whether the structure of these components holds for L2 learners with SLI as well. Students with SLI performed more poorly than typically developing L2 children on auditory perception/phonological conceptualization, speech production/phonological memory, and sentence reproduction constructs. In addition, findings indicated that these same underlying factors (i.e., auditory perception/phonological conceptualization, speech production/phonological memory, lexical-semantic ability, and morphosyntactic ability) were associated with SLI in monolingual and bilingual children. Of the four factors examined in this study, auditory perception/phonological conceptualization was the least stable construct but speech production/phonological memory, lexical-semantic ability, and morphosyntactic ability assessed in the L2 appeared to be stable constructs associated with SLI in bilingual children, just as they are in monolinguals. The study by Tong and McBride (2017) also addressed the consistency of LD profiles across time. These authors set out to check whether dyslexia identified in Chinese for Chinese-English emerging bilingual students was associated also with difficulties in word reading and orthographic skills in English in subsequent years. As part of a larger sample of Chinese-English emerging bilinguals whose language and reading skills were tracked, a group of 11 students was identified as dyslexic in earlier grades. Starting when the children were 9 years old, and for the next 3 years, their word reading skills were compared annually with a group of 14 typically developing students drawn randomly from a larger sample. Compared with the typically developing students, the dyslexic students were more likely to struggle with accurate word reading in English. When assessed again at the age of 13 years, the students with dyslexia had more difficulties than the typically developing comparison group in applying English orthographic rules in an orthographic decision task. Like Chung et al.'s study, results of this study suggest that students who have been identified with dyslexia in their L1 continue to demonstrate difficulties over time with various aspects of word reading, including orthographic processes in their L2. In their article, Lesaux and Harris (2017) used a mixed-methods framework to investigate the reading comprehension processes of 41 Grade 6 or 7 U.S.-born, Spanish-speaking children. This sample was drawn from a larger sample of Spanish-speaking students who participated in a longitudinal study. This group of students was singled out because they performed at or below the 35th percentile on a standardized measure of English reading comprehension. In general, the students in this group of poor comprehenders performed within the average range on decoding skills, but their vocabulary skills were well below national norms. Results of semistructured interviews with students indicated that even though they engaged in various comprehension processes, these poor comprehenders often had imprecise mental representation of the texts they read and were unaware of their own comprehension breakdowns. This study opens a window into metacognitive and language comprehension factors associated with persistent poor comprehension among L2 learners. It also draws attention to a tendency for overestimation of performance by children with LDs, when they rate themselves, a phenomenon claimed to be self-protective by some researchers (e.g., Heath & Glen, 2005). CONCLUSIONS Findings of these studies provide both challenges and opportunities. The use of various approaches to examine development of cognitive, language, and reading skills over time provides converging evidence that, in general, cognitive, language, and reading difficulties of students with LD are stable and persist over time and that some L2 learners may experience persistent reading and language difficulties that cannot be simply understood as reflecting their developing L2 proficiency (Geva & Wiener, 2015). A longitudinal perspective also allows for a more nuanced understanding of relations among variables over time, as exemplified by bootstrapping (Verhoeven et al., 2017). As noted in the introduction, practices and policies resulting in over- or underidentification of L2 children for LD reflect various biases. Research, professional development, and policies are needed to eliminate these biases. Considered jointly, findings of the studies forming this special issue provide converging insights such as the following: (a) some L2 learners have LD or SLI; (b) that the cognitive, language, and reading factor structures that characterize L2 learners with LD are stable (as are those of their typically developing peers); (c) that these structures tend to be similar in the L2 and L1 even when the L1 and L2 are typologically further apart; and (d) that tracking the cognitive, linguistic, and reading skills makes it possible to distinguish L2 students with LD from their typically developing L2 peers. Practically speaking, these studies suggest that it would be prudent to assess and intervene early and that assessment should include an array of language, reading, and cognitive skills, followed, where appropriate, by relevant and timely interventions. These opportunities should not be withheld when L2 learners appear to be having difficulties in comparison with their typically developing L2 peers. Routine collection of data about children's cognitive, language, and reading skills should provide information on whether growth takes place over time. This tracking should facilitate timely, informed, and unbiased screening and focused interventions (Geva & Wiener, 2015). —Esther Geva, PhD, C Psych Issue Editor University of Toronto Ontario Institute for Studies in Education Toronto, Ontario, Canada —Fataneh Farnia, PhD Issue Editor Department of Psychiatry University of Toronto, Toronto, Ontario, Canada