Proto-Celtic *alyos

→ Welsh ail (inherited)

→ Welsh arall (inherited)

→ Welsh llall (inherited)

→ Irish dara (derived)

→ Irish eile (inherited)

→ Scottish Gaelic eile (inherited)

→ Manx elley (inherited)

→ Latin alius (cognate)

→ Middle Irish aile (inherited)

→ Old Irish aile (inherited)

→ Middle Welsh arall (mention)