may refer
Verbo regular: refer - referred- referred

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I may refer
you may refer
he may refer
we may refer
you may refer
they may refer 	I may be referring
you may be referring
he may be referring
we may be referring
you may be referring
they may be referring	I may have referred
you may have referred
he may have referred
we may have referred
you may have referred
they may have referred	I may have been referring
you may have been referring
he may have been referring
we may have been referring
you may have been referring
they may have been referring	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I may not refer
you may not refer
he may not refer
we may not refer
you may not refer
they may not refer 	I may not be referring
you may not be referring
he may not be referring
we may not be referring
you may not be referring
they may not be referring	I may not have referred
you may not have referred
he may not have referred
we may not have referred
you may not have referred
they may not have referred	I may not have been referring
you may not have been referring
he may not have been referring
we may not have been referring
you may not have been referring
they may not have been referring	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
may I refer?
may you refer?
may he refer?
may we refer?
may you refer?
may they refer? 	may I be referring?
may you be referring?
may he be referring?
may we be referring?
may you be referring?
may they be referring? 	may I have referred?
may you have referred?
may he have referred?
may we have referred?
may you have referred?
may they have referred? 	may I have been referring?
may you have been referring?
may he have been referring?
may we have been referring?
may you have been referring?
may they have been referring? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
may I not refer?
may you not refer?
may he not refer?
may we not refer?
may you not refer?
may they not refer? 	may I not be referring?
may you not be referring?
may he not be referring?
may we not be referring?
may you not be referring?
may they not be referring? 	may I not have referred?
may you not have referred?
may he not have referred?
may we not have referred?
may you not have referred?
may they not have referred? 	may I not have been referring?
may you not have been referring?
may he not have been referring?
may we not have been referring?
may you not have been referring?
may they not have been referring?