Meri Huws says her vision is of a Wales where the Welsh language plays a completely central role in public life.
First task of Commissioner:to identify which orgs & companies will be required to comply & to see if they are complying.
Qualifications are: public sector, utilities, telecom companies & businesses receiving more than £400k public money per year.
More top news
Finley Thomas was a "lovely, happy beautiful baby" and changed in the months leading up to his death, a court has heard.
There will be more Welsh athletes than ever before, at this year's World Powerlifting Championships in Texas in June.
Tree pollen levels are easing off now! But beware - grass pollen is just becoming airborne and levels will rise during settled spells.