Ireland
Ireland has two offical languages: Irish and English.
Irish is the national lanuage but only about 4% of people speak it. In the schools they teach Irish all the way from 1st class in primary school up until 6th year in secondary school. They do this to try keep the language alive since it is the national language. Irish speaking people are usually found in the Gaeltacht (Irish speaking towns).
About 95% of people speak English throughout Ireland. English has been spoken in Ireland since the 12th century. Up until then, it was just Irish. Most of the schools if not all speak and write in English. English is much easier for everyone than Irish.
The 1% left speaks any other langauges such as Polish, French, German, Spanish etc.