Complex sentence: Those scholars who believe Proto-Italo-Celtic was an identifiable historical language usually estimate that it was spoken in the third or second millennium BC somewhere in south-central Europe but this hypothesis fell out of favour after being reexamined by Calvert Watkins in 1966.
Split into simpler sentences: Those scholars who believe Proto-Italo-Celtic was an identifiable historical language usually estimate that it was spoken in the third or second millennium BC somewhere in south-central Europe. This hypothesis fell out of favour after being reexamined by Calvert Watkins in 1966.