|58 countries have English as an official language - but not the UK, the USA or Australia.|
According to Henry Hitchings' Language Wars (2011) there are only eight nations which do not have an official primary language.
- UK see here
- USA though 20 states now have one - see here
- Costa Rica
Why these countries?
Each case if unique but there are some common features:
Constitutional history/Cultural tradition
The anglophone countries generally do not have English as an official language. The English language is a shared cultural heritage but not a defining feature of the nation state. Broadly speaking, English has achieved primary status through usage rather than coercion.
A similar pattern can be seen in the emergence of Globish - the form of English used as an international lingua franca.
Language is often a factor in political rivalry between competing communities living in a single nation state. This can lead to political paralysis and ethnic tension - see Belgium, for example.
According to the Ethnologue, the area that once formed Ethiopia has 84 native languages. This may explain why the three neighbouring African countries: Ethiopia, Somalia & Eritrea have avoided giving one linguistic community privileged status.
Religious/Ethnic TensionPakistan is a nation essentially created on religious grounds, also containing a number of competing communities. Urdu is the de facto official language, only this arrangement is not formalised as is the case with its close cousin Hindi in India.
In Bosnia language has also been a proxy for wider ethnic tension. It has wisely avoided opening a linguistic battlefield after the civil war of the 1990s.
Protecting minority languagesCosta Rica does not have the obvious political tensions that usually makes language contentious. It has historically been the most stable democracy in Latin America. But though Spanish dominates, the Bribri, Maléku, Cabécar and Ngäbere languages are still spoken in indigenous reservations.
Around 10.7% of Costa Rica's adult population also speaks Creole-English. Creole speakers live largely around the Caribbean coast.
New Zealand also promotes minority languages (Maori & New Zealand Sign Language) through official status. New Zealand Sign Language (with less than 25,000 speakers) is official while English, the mother tongue of 95.6% of the population, is not.
Sometimes protecting indigenous minority languages can produce strange anomalies. My parents were educated entirely in Irish despite neither ever having spoken the language.