Within the Celtic family, Welsh has as its closest relatives: Breton (Welshname Llydaweg), spoken in Brittany – estimates of number of speakersvary, but probably somewhat under half a million active users; and Cornish(Cernyweg), extinct since the late eighteenth century, though recently‘resurrected’ by enthusiasts. More distantly related are Irish (Gwyddeleg),Scots Gaelic (Gaeleg yr Alban) and the extinct Manx (Manaweg, whoselast native speaker died in 1974). Welsh, Breton and Cornish constitute theBrythonic group, while the others form the Goidelic group. There arestrong similarities within each group, and considerable differences betweenthe two. All six languages share certain basic characteristics which markthem out as Celtic languages – notably the mutation system (see §§3–12),and inflected prepositions (see §446).