must preascertain
Verbo regular: preascertain - preascertained- preascertained

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must preascertain
you must preascertain
he must preascertain
we must preascertain
you must preascertain
they must preascertain 	I must be preascertaining
you must be preascertaining
he must be preascertaining
we must be preascertaining
you must be preascertaining
they must be preascertaining	I must have preascertained
you must have preascertained
he must have preascertained
we must have preascertained
you must have preascertained
they must have preascertained	I must have been preascertaining
you must have been preascertaining
he must have been preascertaining
we must have been preascertaining
you must have been preascertaining
they must have been preascertaining	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't preascertain
you mustn't preascertain
he mustn't preascertain
we mustn't preascertain
you mustn't preascertain
they mustn't preascertain 	I mustn't be preascertaining
you mustn't be preascertaining
he mustn't be preascertaining
we mustn't be preascertaining
you mustn't be preascertaining
they mustn't be preascertaining	I mustn't have preascertained
you mustn't have preascertained
he mustn't have preascertained
we mustn't have preascertained
you mustn't have preascertained
they mustn't have preascertained	I mustn't have been preascertaining
you mustn't have been preascertaining
he mustn't have been preascertaining
we mustn't have been preascertaining
you mustn't have been preascertaining
they mustn't have been preascertaining	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I preascertain?
must you preascertain?
must he preascertain?
must we preascertain?
must you preascertain?
must they preascertain? 	must I be preascertaining?
must you be preascertaining?
must he be preascertaining?
must we be preascertaining?
must you be preascertaining?
must they be preascertaining? 	must I have preascertained?
must you have preascertained?
must he have preascertained?
must we have preascertained?
must you have preascertained?
must they have preascertained? 	must I have been preascertaining?
must you have been preascertaining?
must he have been preascertaining?
must we have been preascertaining?
must you have been preascertaining?
must they have been preascertaining? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I preascertain?
mustn't you preascertain?
mustn't he preascertain?
mustn't we preascertain?
mustn't you preascertain?
mustn't they preascertain? 	mustn't I be preascertaining?
mustn't you be preascertaining?
mustn't he be preascertaining?
mustn't we be preascertaining?
mustn't you be preascertaining?
mustn't they be preascertaining? 	mustn't I have preascertained?
mustn't you have preascertained?
mustn't he have preascertained?
mustn't we have preascertained?
mustn't you have preascertained?
mustn't they have preascertained? 	mustn't I have been preascertaining?
mustn't you have been preascertaining?
mustn't he have been preascertaining?
mustn't we have been preascertaining?
mustn't you have been preascertaining?
mustn't they have been preascertaining?