There is no one Celtic language. Celtic languages (with an 's') are a group of languages ariginating in Europe. Germanic languages are a group of languages also originating in Europe and include...
The Celtic languages are part of a group called the Italo-Celtic branch of the Indo-European family of languages, which arose somewhere in Eastern Europe.
Language groups, or language families, are, as their name suggests, a way of categorising languages according to their origins. As there are several levels of categorisation, each language will...