History has shown us that the use of the language within a community can decline with alarming speed - and this decline can be seen today in many parts of Wales.
Mae hanes wedi dangos i ni y gall y defnydd o'r iaith o fewn i gymuned leihau’n eithriadol o gyflym - a gellir gweld y dirywiad hwn heddiw mewn sawl rhan o Gymru