Old Irish do

← Proto-Celtic *do (inherited)

← Proto-Indo-European *de (derived)

← Old Irish to- (mention)

→ Old English to (cognate)

→ Irish do (inherited)

→ Irish do (inherited)

→ Scottish Gaelic do (inherited)

→ Scottish Gaelic do (inherited)

→ Manx da (derived)

→ Manx dty (inherited)

→ Old Irish dia (affix)

→ Old Irish dún (mention)

→ Old Irish dúnn (mention)

→ Old Irish dóer (prefix)