Use of a single language in a multi-cultural setting leads to difficulties and resentment. Speakers using a foreign language have their confidence undermined, and are relegated to using simplistic terms which may not necessarily convey the subtleties or power of their argument. This prevents their audience from understanding the point, which therefore does not receive its full attention. The foreign speaker is left with a feeling of frustration and inadequacy at finding himself unable to make the full contribution he would otherwise be capable of. As language conditions those who use it, speakers gradually identify themselves with the language and the culture it incarnates. Non-speakers of a foreign language may therefore experience it as a threat to their identity. Monolingualism renders speakers unexposed to the variety of alternative concepts, structures and perceptions that exist in other languages; creating a gap between the educated elite speaking the single language and the people in the many other cultures on which the monolingualism is effectively imposed.
Another concern raised by the domination of one language in a multi-cultural environment is the dominant language's eventual disappearance, due to its simplification as a means of communication between native and non-native speakers. Simplification of a language, which usually includes the loss of strict grammatical rules and sophisticated expressions, may eventually render the language useless for detailed communication. Consequently, the once dominant language may dissipate and separate languages may emerge from those speakers of different linguistic backgrounds. Such was the fate of the Latin language, which some fear bore resemblance to the existence of the English language today.
An historical example of monolingualism in multi-cultural settings is the imposition of Latin by the Romans in order to administratively unify their empire. More recent examples include Spanish and French military and cultural imperialism prior to World War II; the imposition of Russian in Ukrainia Georgia, and in post-war Warsaw Pact relations; the dominance of official Hindi in India; official Mandarin and Pin-yin in China; and Swahili in East Africa. The most evident example is the increasing use of English in international relationships of varying types.