We believe that knowing two or more languages and being able to use them appropriately and effectively is a personal, social, professional, and societal asset. - Johanne Paradis, Fred Genesee, and Martha B. Crago (2011, p. 5)

In this issue of Topics in Language Disorders (TLD), Issue Editors, Drs. Esther Geva and Fataneh Farniah from the University of Toronto, make a substantive contribution to the knowledge base on second language (L2) and literacy learning by school-aged children and adolescents. The five articles in this issue present findings from researchers who have conducted, as the issue title conveys, Longitudinal Research on the Language and Literacy Skills of Typically and Nontypically Developing Students in Their Second Language. Beyond contributing to basic understandings, this issue has practical implications for identifying and working with students who are demonstrating language disorders and learning disabilities, including dyslexia, in their second language, as well as their first. As Geva and Farnia (2017) note in their Issue Editor Foreword, such information is needed to dispel biases that have led to "practices and policies resulting in over- or underidentification of L2 children" (p. x).

To get the most out of this issue, my recommendation is to start by reading the Issue Editor Foreword (Geva & Farnia, 2017). It provides a clear framework for constructing the broader picture from the five articles that constitute the issue. The articles differ in the questions asked, methods used, and populations studied, but they share focus on the cognitive, language, and reading (word-level and comprehension) abilities among school-aged children as they learn a second language.

Swanson (2017) contributes findings regarding cognitive factors associated with language and literacy development for three groups of readers in the United States whose home language is Spanish but who are learning to read in English. Chung, Koh, Deacon, and Chen (2017) contribute information about students attending a French immersion program in Canada regarding their early-grade cognitive, language, and reading skills in English and French as predictors of later word reading and higher level literacy skills. Verhoeven, Steenge, van Leeuwe, and van Balkom (2017) contribute information about children in the Netherlands whose home language is Turkish, Moroccan, or Surinamese and who have been identified with specific language impairment from the perspective of spoken language components underlying their language abilities in Dutch. Tong and McBride (2017) contribute information about children in Hong Kong who demonstrate dyslexia in Chinese regarding their abilities to perform word reading and orthographic tasks in English. Finally, Lesaux and Harris (2017) contribute quantitative and qualitative information about reading comprehension as measured in, and described by, students in the United States who are children of Spanish-speaking immigrants.

Overall, this issue of TLD provides a rich tapestry with textures and colors representing typical and atypical language and literacy learning across languages and cultures, but with repeated and interwoven themes. As scientists and clinicians, we remain a long way from understanding the exact nature of the cognitive-linguistic factors that allow some children to learn their first language and any additional languages without difficulty, whereas others, with equally high intelligence, struggle. An important take-home message, however, is that even when there are typological differences between languages in terms of phonology, morphology, orthography, vocabulary, and syntax, children and adolescents who struggle with one or more of these aspects in one language are likely to have parallel problems learning another. That does not mean that they cannot reap the "personal, social, professional, and societal" benefits of being multilingual, as expressed by Paradis, Genesee, and Crago (2011, p. 5) in the opening quotation to this column. It does mean, however, that such children and adolescents should be identified and evaluated comprehensively and in a timely fashion so that they can gain access to the intervention services they may need to acquire those assets. The information in this issue makes a substantive contribution to the knowledge of professionals who seek to develop those tools and provide those services.

-Nickola Wolf Nelson, PhD

Editor-in-Chief

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