1)qu------------car
2)gu--------------gar
3)c------------------zar
This could be to show how some sounds need to have different spelling in order to maintain the same sound
Empezar------------empecemos(change from z to c)
z+a,o,u c +e ,i
Jugar---------------juguemos (from g to gu)
g +a o u gu + e ,i
Embarcar-----------embarquemos(from c to qu)
c+a,o,u qu+ e,i