'ir' or 'ur' in th___d
'ir' in third
'ir' or 'ur' in c___cus
'ir' in circus
'ir' or 'ur' in p___se
'ur' in purse
'ir' or 'ur' in h___t
'ur' in hurt
'ir' or 'ur' in d___ty
'ir' in dirty
'ir' or 'ur' in p___ple
'ur' in purple
'ir' or 'ur' in sh___t
'ir' in shirt
'ir' or 'ur' in th___ty
'ir' in thirty
'ir' or 'ur' in b___thday
'ir' in birthday
'ir' or 'ur' in n___se
'ur' in nurse
'ir' or 'ur' in f___
'ur' in fur
'ir' or 'ur' in b___n
'ur' in burn
'ir' or 'ur' in th___sty
'ir' in thirsty
'ir' or 'ur' in t___key
'ur' in turkey
'ir' or 'ur' in c___cle
'ir' in circle
'ir' or 'ur' in hamb___ger
'ur' in hamburger
'ir' or 'ur' in s___f
'ur' in surf
'ir' or 'ur' in b___d
'ir' in bird
'ir' or 'ur' in sk___t
'ir' in skirt
'ir' or 'ur' in t___tle
'ur' in turtle (Don't try this with yours!)
'ir' or 'ur' in g___l
'ir' in girl
'ir' or 'ur' in Th___sday
'ur' in Thursday
'ir' or 'ur' in f___st
'ir' in first