Welsh pa

← Proto-Celtic *kʷid (inherited)

← Irish cad (cognate)

← Proto-Indo-European *kʷid (inherited)

← Proto-Indo-European *kʷis (mention)

← Cornish py (cognate)

← Cornish pe (mention)

← Latin quid (cognate)

← Old Irish cid (cognate)

→ Welsh pam (compound)

→ Welsh beth (mention)

→ Old Irish cid (cognate)