may tighten
Verbo regular: tighten - tightened- tightened

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I may tighten
you may tighten
he may tighten
we may tighten
you may tighten
they may tighten 	I may be tightening
you may be tightening
he may be tightening
we may be tightening
you may be tightening
they may be tightening	I may have tightened
you may have tightened
he may have tightened
we may have tightened
you may have tightened
they may have tightened	I may have been tightening
you may have been tightening
he may have been tightening
we may have been tightening
you may have been tightening
they may have been tightening	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I may not tighten
you may not tighten
he may not tighten
we may not tighten
you may not tighten
they may not tighten 	I may not be tightening
you may not be tightening
he may not be tightening
we may not be tightening
you may not be tightening
they may not be tightening	I may not have tightened
you may not have tightened
he may not have tightened
we may not have tightened
you may not have tightened
they may not have tightened	I may not have been tightening
you may not have been tightening
he may not have been tightening
we may not have been tightening
you may not have been tightening
they may not have been tightening	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
may I tighten?
may you tighten?
may he tighten?
may we tighten?
may you tighten?
may they tighten? 	may I be tightening?
may you be tightening?
may he be tightening?
may we be tightening?
may you be tightening?
may they be tightening? 	may I have tightened?
may you have tightened?
may he have tightened?
may we have tightened?
may you have tightened?
may they have tightened? 	may I have been tightening?
may you have been tightening?
may he have been tightening?
may we have been tightening?
may you have been tightening?
may they have been tightening? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
may I not tighten?
may you not tighten?
may he not tighten?
may we not tighten?
may you not tighten?
may they not tighten? 	may I not be tightening?
may you not be tightening?
may he not be tightening?
may we not be tightening?
may you not be tightening?
may they not be tightening? 	may I not have tightened?
may you not have tightened?
may he not have tightened?
may we not have tightened?
may you not have tightened?
may they not have tightened? 	may I not have been tightening?
may you not have been tightening?
may he not have been tightening?
may we not have been tightening?
may you not have been tightening?
may they not have been tightening?