valve was stuck on 2001 Toyota Celica

ok so this is my gfs car and i havent got into it to see whats up. but from what she says it had a stuck valve and she got it fixed but a few days after, it started burning 2 quarts of oil every few days. whats wrong with it?

Asked by for the 2001 Toyota Celica
By a "stuck valve" it is unlikely to be an intake or exhaust valve that stuck unless a serious oil starvation issue occurred after which the valve and valve guide would have been scuffed and galled. Oil consumption may be caused by a bad PCV (Positive Crankcase Ventilation Valve) may have failed. To consume that much oil the engine may have bad valve guides, bad valve guide seals, bad piston rings or cylinder or piston damage.