This Special Issue of Applied Psycholinguistics includes the third Keynote Article in our Journal. This format has been very successful, and thus far it has generated fruitful discussions in two areas of research: the relationship between nonword repetition and word learning (Gathercole, Reference Gathercole2006) and grammatical processing in language learners (Clahsen & Felser, Reference Clahsen and Felser2006).

It gives me great pleasure to introduce the third Keynote Article by Johanne Paradis, which focuses on a relatively new research area: the interface between bilingual development and specific language impairment (SLI). Johanne Paradis has played a leading role in this field in the last 10 years by conducting a series of studies comparing the profiles of bilingual children and children with SLI. Therefore, I was delighted when she accepted our invitation to write this Keynote Article. The Keynote reviews research in the field, brings the focus to theoretical issues, and highlights clinical implications. We are honored that eminent researchers from the fields of bilingualism, SLI, and the interface between the two have provided thoughtful and thorough Commentaries. This has opened up an in-depth discussion on both theoretical and clinical issues and, as such, is promising in moving the field of bilingual development and SLI forward in a significant way.