Bristol, Cheshire West and Chester, Shropshire and Liverpool had the largest proportions of people with Welsh as their main language (0.1% each).
Roedd y cyfrannau mwyaf o bobl a ddewisodd y Gymraeg fel eu prif iaith (0.1% yr un) ym Mhryste, Gorllewin Swydd Gaer a Swydd Gaer, Swydd Amwythig a Lerpwl .