Proto-Italic *kʷettwōr

→ Cebuano kwatro (derived)

→ Corsican quattru (inherited)

→ Spanish cuatro (inherited)

→ Italian quattro (inherited)

→ Latin quattuor (inherited)

→ Ligurian quàttro (inherited)

→ Oscan 𐌐𐌄𐌕𐌖𐌓𐌀 (inherited)

→ Oscan 𐌐𐌄𐌕𐌕𐌉𐌖𐌓 (inherited)

→ Old Spanish quatro (derived)

→ Piedmontese quatr (inherited)

→ Portuguese quatro (inherited)

→ Romanian patru (inherited)

→ Aromanian patru (inherited)

→ Sardinian bator (inherited)