Gaulish (with its dialects Lepontic and Galatian) is a member of the (continental) Celtic branch of the Indo-European language family.  It was spoken form the Asia minor, through Italy up to the British channel and later, it was used also in the British Isles. The earliest Lepontic texts come from 600 BC, the Cisalpine Gaulish inscriptions come from the 200-0 BC, Transalpine Gaulish in the 3rd century BC, Celtiberian from 200BC – 200 AD. The corpus is the largest of the Continental Celtic languages, consisting of over 760 inscriptions (though many contain only few words, often names), and texts were written in north Etruscan alphabet (Lepontic and Cisalpine Gaulish), Greek script and later in Roman characters. Gaulish words are also known from texts of other languages.

The Continental Celtic corpus consists (besides lexemes found in texts of other languages) of inscriptions on stone, metal, ceramics and coins and is very fragmentary.

Lepontic corpus consists of inscriptions on coins coins (one-word, less than 18, possibly only two), other inscriptions (very short, usualy one-word), objects (typicaly inscribed  with a single word) and sources from other languages.

Nominals could inflect in two numbers (singular, plural) and possibly dual, for three genders (feminine, masculine, neuter) and in eight cases (nominative, accusative, genitive,dative, locative, instrumental, ablative, vocative). All forms are not attested for all of the Continental Celtic languages. It did not use infinitives but nominalized verbs (three attested in Celtiberian, Eska 2008:178). Participles were more frequent – there were the present active, mediopassive and passive participles.

Bibliography:

Eska, Joseph F.  and Ellis D. Evans. 2010. Continental Celtic. In: Martin J. Ball and Nicole Müller (eds.), The Celtic languages. London &New York: Routledge, 28-54

Eska, Joseph F. 2008. Continental Celtic. In: Woodard R. (ed.), The Ancient Languages of Europe. Cambridge: Cambridge University Press, p. 165-189.

Online: Lexicon Leponticum, http://www.univie.ac.at/lexlep/wiki/Main_Page.