This issue offers a multi-faceted view of urban multilingualism. It does so from a specific point of view, focusing on the relationship between structures and agencies, that is, between:-established routines, structures and policies that exert a determining influence on local interactions; and -local interactional practices that show people working with, appropriating, neutralising or avoiding established routines to reconcile the linguistic demands of urban institutions and the interactional business-on-hand.With case studies from the U.S., the U.K., Spain, Portugal, the Netherlands and Belgium, this issue attempts to provide a descriptive link between structures and practices, global questions and situated responses in a diversity of institutional contexts and approached from different methodological angles.Many readers will agree that the practice of studying multilingualism has very often involved a certain measure of rowing against the current, or depended on a form of sub-altern agency. Certainly within the more linguistically oriented areas of the academy, scholars interested in bi-or multilingualism had for long to work in defiance of a customary, and essentially nationalist, 'monolingual mind-set' (cf. Clyne, 2005: xi, cf. Farr, this issue); and they were compelled to sing out of tune with a hegemonic preference for retrieving systematicity in individual speakers' cognitive abilities for producing language rather than for describing and explaining how language is used between speakers -let alone how two or more languages, or mixed versions of them, can function as meaningful communicative tools. Consequently, under these structural conditions attending to multilingual practices often entailed doing scholarly work as much as legitimizing and normalizing it. As an indication of the importance and the strength of this legitimizing reflex, Auer and Wei (2007) still anticipate it when they make explicit efforts to allay worries that their applied linguistic focus on multilingualism contributes to its problematization and subsequently reassure their readership that their interest is in how multilingualism is turned into a problem, adding that ''far from being a problem, multilingualism is part of the solution for our future. Social stability, economic development, tolerance and cooperation between groups is possible only when multilingualism is respected' ' (2007: 12). Also outside of the academy, scholars of multilingualism have -with varying success -frequently stuck their necks out to rub against common-sense views of language and point out the negative impact of these views for the lives of bilinguals, speakers of minority, lesser-used or endangered languages, most clearly visible in the fields of 'linguistic human rights ' (see, e.g