Answer and Explanation:
If a city has two large language communities, it should make teaching both languages mandatory. That way, the prevalence of one language over the other in daily use could be prevented. Both languages would be equally known by inhabitants and, consequently, in areas where one language prevails already, there would be no reason to force communication in the other language. Another reason for teaching both languages is that children's brains develop differently when they are given a bilingual education. Bilingual children tend to have better memory, performance in creative tasks, and academic performance, as well as more job opportunities in the future.