Societal multilingualism and multilectalism have been among the leading justifications for language policies, especially in the Global South, where many of these have failed. I associate the failures with poor choices of official languages and media of education, which are not consistent with the linguistic behaviors of the majority of the citizenry and the socioeconomic structures of the relevant polities. I review some cases of adequate and inadequate policies around the world and explain ecologically some reasons for either their successes or their failures. In a subset of the cases, I assess the results as mixed. My recommendation is of course not to follow the policy of a particular polity simply because it has succeeded there but to also check whether the ecology of its success is similar to that of the new polity. The relevant ecology includes the socioeconomic structure/system and the linguistic practices of the citizenry for whom the policy is intended. Among the issues to address is, for instance, whether the language adopted as the official language and medium of education is easy for the majority of the citizenry to learn successfully. Another is whether the language policy will make the economic development of the nation more inclusive and empower the majority economically and politically.