must crust
Verbo regular: crust - crusted- crusted

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must crust
you must crust
she must crust
we must crust
you must crust
they must crust 	I must be crusting
you must be crusting
she must be crusting
we must be crusting
you must be crusting
they must be crusting	I must have crusted
you must have crusted
she must have crusted
we must have crusted
you must have crusted
they must have crusted	I must have been crusting
you must have been crusting
she must have been crusting
we must have been crusting
you must have been crusting
they must have been crusting	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must not crust
you must not crust
she must not crust
we must not crust
you must not crust
they must not crust 	I must not be crusting
you must not be crusting
she must not be crusting
we must not be crusting
you must not be crusting
they must not be crusting	I must not have crusted
you must not have crusted
she must not have crusted
we must not have crusted
you must not have crusted
they must not have crusted	I must not have been crusting
you must not have been crusting
she must not have been crusting
we must not have been crusting
you must not have been crusting
they must not have been crusting	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I crust?
must you crust?
must she crust?
must we crust?
must you crust?
must they crust? 	must I be crusting?
must you be crusting?
must she be crusting?
must we be crusting?
must you be crusting?
must they be crusting? 	must I have crusted?
must you have crusted?
must she have crusted?
must we have crusted?
must you have crusted?
must they have crusted? 	must I have been crusting?
must you have been crusting?
must she have been crusting?
must we have been crusting?
must you have been crusting?
must they have been crusting? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I not crust?
must you not crust?
must she not crust?
must we not crust?
must you not crust?
must they not crust? 	must I not be crusting?
must you not be crusting?
must she not be crusting?
must we not be crusting?
must you not be crusting?
must they not be crusting? 	must I not have crusted?
must you not have crusted?
must she not have crusted?
must we not have crusted?
must you not have crusted?
must they not have crusted? 	must I not have been crusting?
must you not have been crusting?
must she not have been crusting?
must we not have been crusting?
must you not have been crusting?
must they not have been crusting?