If I were counting one to five using the words: Bat, Bi, Hiru, Lau, Bost, what language would I be speaking?

I would be speaking the Basque language or Euskara as it is known in Basque. It is what is known as an "orphan language" as it is a language without any known linguistic relatives. Its sole connection is to its own ancestor known as Aquitanian that was recorded in latin inscriptions in the 1st and 2nd centuries. Basque is spoken by some 660,000 out of some three million who live in the Basque Country (some in an autonomous area) in the north of Spain and South West France, roughly between the western Pyrenees mountains and along Bay of Biscay. The territory is known in Basque as Euskal Herria and its capital and largest city is Bilbao. The indigenous people have been shown to predate the arrival of agriculture about 7000 years ago and their language is thought to predate the spread of Indo-European languages to which it is not related.