Without a doubt, the most prestigious status for any language is that of official language, because states or countries that grant it automatically commit to using that language in all of their operations. Of the world's 6,000 to 7,000 languages, only about 100 stand as the official languages of one or more countries, be they native languages (endogenous) or non-native (exogenous). In addition, countries with only one official language can still boast many other spoken languages within their borders, but the state itself uses nothing but the official language.

Co-official status can be granted to two languages, or even to three or four, and this means the state commits to using each and every one. When languages are declared co-official, they are subject to two determining factors: equality of status and territorial organization. One must remember that countries can proclaim two languages as official, yet give them a different legal status-and this can result in one language becoming more official than the other and, to a degree, predominant.

From the territorial perspective, three options come to light:

  1. make the languages in question co-official across the entire country (focus on individual rights);
  2. resort to unilingualism to separate the languages inside the country (focus on territorial rights);
  3. declare a single language official everywhere and impose bilingualism regionally (blended formula).

Unilingualism policies can operate locally, and this is known as territorial unilingualism (Swiss cantons, Belgium's French-, Flemish- and German-speaking communities, Bosnia and Herzegovina). In all of these cases, the central government operates under bilingualism, trilingualism or quadrilingualism.

For comparison's sake, Canada's federal government matches option a); Switzerland fits option (b), and Spain option (c). In Canada, only the province of New Brunswick has adopted official bilingualism and, in principle at least, this co-officiality allows its citizens to use either of the official languages when dealing with the government.

Policies on official multilingualism enshrine the equality of two or more languages in a constitution or in legislation; this equality is a strictly legal one and doesn't always become reality in day-to-day life. The status gives citizens the right to use one or the other official language when they deal with the state. So, this linguistic choice normally represents a right for individuals and an obligation for the state.

Interestingly, only 20% (40) of the world's sovereign states practise this type of institutional multilingualism. The others, of course, have official unilingualism (80%).

Multilingual countries practising multilingualism on the basis of individual rights (non-territorial):

- Byelorussia
- Botswana
- Burundi
- Canada (federation)
- Central African Republic
- Chad
- Djibouti
- Guam
- Ireland

- Kenya
- Kyrgyzstan
- Kiribati
- Lesotho
- Malta
- Marshall Islands
- Nauru
- New Zealand
- Niue

- Norway
- Rwanda
- South Africa (federation)
- Swaziland
- Tanzania
- Tokelau Islands
- Tonga
- Tuvalu
- Western Samoa

Multilingual countries practising multilingualism on the basis of territorially determined individual rights : Finland, Federated States of Micronesia, Nicaragua.

Multilingual countries practising multilingualism on the basis of territorial rights: Belgium, Switzerland and Cameroon.

Non-sovereign states (Canadian provinces, Belgian linguistic communities, Swiss cantons, states of the Indian Union, states of South Africa, Spain's autonomous communities, Denmark's territories, the republics, territories, regions, autonomous regions and districts of the Russian Federation, etc.), provided they possess some sort of legislative, executive and, often, judiciary authority, generally have the same official language as their respective central government, but they can in many cases choose one or several more official languages.