Encouraging people to use their Welsh in all situations is the aim of the Welsh Language Commissioner's campaign and some of Wales' most prominent names are offering their support this year.
Annog pobl i ddefnyddio eu Cymraeg ymhob sefyllfa yw nod ymgyrch Comisiynydd y Gymraeg ac mae rhai o sȇr amlycaf Cymru yn cynnig eu cefnogaeth eleni.