The effects of language are numerous. Some are known and have been described, other effects are intuitive and are still waiting to be understood, explained and predicted, while – possibly – there might be more effects that we are still unaware of. The book brings together 16 contributions organized into two main sections: The first one relates to the issue of the effects of language in the FL classroom. The second one can, broadly speaking, be subsumed under the heading of sociolinguistics, given that it brings together a number of papers exploring the effects of language on society and/or on the individual. The answers to the questions have been provided by linguists – theoreticians and practitioners - from multiple perspectives. Thus, the conclusions and invitations for further research put forth in the papers collected in this book, should be of use to anyone with an interest in the effects of language, from cognitive scientists to FL teachers.