Welsh (Cymraeg or y Gymraeg, pronounced [kəmˈrɑːɨɡ, ə ɡəmˈrɑːɨɡ]) is a member of the Brythonic branch of the Celtic languages spoken natively in Wales, by some along the Welsh border in England, and in Y Wladfa (the Welsh colony in Chubut Province, Argentina). Historically it has also been known in English as "the British tongue", "Cambrian", "Cambric" and "Cymric".
The 2011 UK Census counted almost 3 million residents of Wales. Of these, 73% (2.2 million) reported having no Welsh language skills. Of the residents of Wales aged three and over, 19% (562,000) reported being able to speak Welsh, and 77% (431,000) of these (that is, 15% of the total population) were able to speak, read, and write the language. This can be compared with the 2001 Census, in which 20.8% of the population (582,000) reported being able to speak Welsh. In surveys carried out between 2004 and 2006, 57% (315,000) of Welsh speakers described themselves as fluent in the written language.
A greeting in Welsh is one of 55 languages included on the Voyager Golden Record chosen to be representative of Earth in NASA's Voyager program launched in 1977. The greetings are unique to each language, with the Welsh greeting being Iechyd da i chwi yn awr ac yn oesoedd which translates into English as "Good health to you now and forever".
The Welsh Language (Wales) Measure 2011 Act gave the Welsh language official status in Wales, making it the only language that is de jure official in any part of the United Kingdom. (from Wikipedia)