must lighten
Verbo regular: lighten - lightened- lightened

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must lighten
you must lighten
he must lighten
we must lighten
you must lighten
they must lighten 	I must be lightening
you must be lightening
he must be lightening
we must be lightening
you must be lightening
they must be lightening	I must have lightened
you must have lightened
he must have lightened
we must have lightened
you must have lightened
they must have lightened	I must have been lightening
you must have been lightening
he must have been lightening
we must have been lightening
you must have been lightening
they must have been lightening	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must not lighten
you must not lighten
he must not lighten
we must not lighten
you must not lighten
they must not lighten 	I must not be lightening
you must not be lightening
he must not be lightening
we must not be lightening
you must not be lightening
they must not be lightening	I must not have lightened
you must not have lightened
he must not have lightened
we must not have lightened
you must not have lightened
they must not have lightened	I must not have been lightening
you must not have been lightening
he must not have been lightening
we must not have been lightening
you must not have been lightening
they must not have been lightening	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I lighten?
must you lighten?
must he lighten?
must we lighten?
must you lighten?
must they lighten? 	must I be lightening?
must you be lightening?
must he be lightening?
must we be lightening?
must you be lightening?
must they be lightening? 	must I have lightened?
must you have lightened?
must he have lightened?
must we have lightened?
must you have lightened?
must they have lightened? 	must I have been lightening?
must you have been lightening?
must he have been lightening?
must we have been lightening?
must you have been lightening?
must they have been lightening? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I not lighten?
must you not lighten?
must he not lighten?
must we not lighten?
must you not lighten?
must they not lighten? 	must I not be lightening?
must you not be lightening?
must he not be lightening?
must we not be lightening?
must you not be lightening?
must they not be lightening? 	must I not have lightened?
must you not have lightened?
must he not have lightened?
must we not have lightened?
must you not have lightened?
must they not have lightened? 	must I not have been lightening?
must you not have been lightening?
must he not have been lightening?
must we not have been lightening?
must you not have been lightening?
must they not have been lightening?