"Over the past 20 years there has been a gradual erosion in productions of English language theatreand it's almost disappeared in many areas, " he said.
The teenager has also performed with both English National Ballet and American Ballet Theatre at the Coliseum in London in performances of Nutcracker and Le Corsaire.
Boyle studied Englishand drama at university, before working at the RSC and at London's innovative Royal Court Theatre, where he was deputy director in the 1980s.
It also said the range and volume of English language production in Wales had been dropping, with the result that audiences were declining and much theatre talent was forced to work outside Wales.