Irish cad

← Proto-Celtic *kʷid (inherited)

← Proto-Indo-European *kʷid (inherited)

← Proto-Indo-European *kʷis (mention)

← Old Irish cid (inherited)

→ Old English hwæt (cognate)

→ Welsh pa (cognate)

→ Irish cad ina thaobh (compound)

→ Scottish Gaelic ciod (cognate)