Who are adolescents and adults who develop literacy for the first time in an L2, and why are they of research interest?

This Special Issue concerns a special population of second-language learners: post-puberty second-language (L2) learners who are learning to read and write for the first time in their lives, in the second language they are in the process of acquiring. They are among the roughly 781 million adult illiterates worldwide (UNESCO, 2014), and among those who emigrate from politically instable and/or impoverished regions of the world to highly literate post-industrialised societies. Theirs is a unique learning situation. Children learning to read in their home language begin with a language they know. They know the phonology, morphology and syntax of that language, and they know most if not all of the words they come across in reading materials designed for them. Their linguistic competence confers a range of advantages at the initial stages of reading. They are able to develop metalinguistic knowledge and skills to facilitate learning to read based on their linguistic competence. Attempts to guess words can be based on predictions of the next consonant in a cluster or of a possible word following a transitive verb. Much has been written about children’s reading development. Much has also been written about the development of reading by second-language learners, including those learning to read in a writing system different from their native language (Koda, 2005). The older learners studied are invariably educated and can already read and write in their native language. The younger learners studied may be foreign language learners in school or immigrant children who, like their older siblings and parents, need to learn to read in a language different from their home language. Here, too, there is a good amount of research (e.g., Gersten & Geva, 2003; Grigorenko & Takanishi, 2009). Older uneducated and low-educated L2 learners have long been neglected by researchers, despite the fact that more now fit the profile of the uninstructed migrant workers in northern Europe who in the 1970s and 1980s attracted considerable research attention (see Young-Scholten, 2013). The amount of research on the language and literacy development of older non-/low-educated L2 learners is surprisingly small. Increased basic research on both the internal and external factors which correlate with language and literacy success for these severely disadvantaged adults would yield evidence on which to