What was the name of language Celts spoke?

There's no single answer to that question! The Celts were a diverse group of people spread across Europe, and they spoke a variety of languages. These languages are collectively referred to as Celtic languages, but they are not a single unified language.

Here are some key things to keep in mind:

* Different Branches: Celtic languages are divided into two main branches: Insular Celtic (spoken in Ireland, Scotland, Wales, Cornwall, and the Isle of Man) and Continental Celtic (spoken in mainland Europe).

* Extinct Languages: Many Continental Celtic languages are extinct, such as Gaulish (spoken in ancient Gaul) and Celtiberian (spoken in the Iberian Peninsula).

* Surviving Languages: Insular Celtic languages are still spoken today, including:

* Irish (Gaeilge)

* Scottish Gaelic (Gàidhlig)

* Manx (Gaelg)

* Welsh (Cymraeg)

* Cornish (Kernewek)

* Breton (Brezhoneg)

So, while we can't pinpoint a single language as the "Celtic" language, we can say that the Celts spoke a family of languages that have left a lasting impact on the world.