must precheck
Verbo regular: precheck - prechecked- prechecked

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must precheck
you must precheck
he must precheck
we must precheck
you must precheck
they must precheck 	I must be prechecking
you must be prechecking
he must be prechecking
we must be prechecking
you must be prechecking
they must be prechecking	I must have prechecked
you must have prechecked
he must have prechecked
we must have prechecked
you must have prechecked
they must have prechecked	I must have been prechecking
you must have been prechecking
he must have been prechecking
we must have been prechecking
you must have been prechecking
they must have been prechecking	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't precheck
you mustn't precheck
he mustn't precheck
we mustn't precheck
you mustn't precheck
they mustn't precheck 	I mustn't be prechecking
you mustn't be prechecking
he mustn't be prechecking
we mustn't be prechecking
you mustn't be prechecking
they mustn't be prechecking	I mustn't have prechecked
you mustn't have prechecked
he mustn't have prechecked
we mustn't have prechecked
you mustn't have prechecked
they mustn't have prechecked	I mustn't have been prechecking
you mustn't have been prechecking
he mustn't have been prechecking
we mustn't have been prechecking
you mustn't have been prechecking
they mustn't have been prechecking	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I precheck?
must you precheck?
must he precheck?
must we precheck?
must you precheck?
must they precheck? 	must I be prechecking?
must you be prechecking?
must he be prechecking?
must we be prechecking?
must you be prechecking?
must they be prechecking? 	must I have prechecked?
must you have prechecked?
must he have prechecked?
must we have prechecked?
must you have prechecked?
must they have prechecked? 	must I have been prechecking?
must you have been prechecking?
must he have been prechecking?
must we have been prechecking?
must you have been prechecking?
must they have been prechecking? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I precheck?
mustn't you precheck?
mustn't he precheck?
mustn't we precheck?
mustn't you precheck?
mustn't they precheck? 	mustn't I be prechecking?
mustn't you be prechecking?
mustn't he be prechecking?
mustn't we be prechecking?
mustn't you be prechecking?
mustn't they be prechecking? 	mustn't I have prechecked?
mustn't you have prechecked?
mustn't he have prechecked?
mustn't we have prechecked?
mustn't you have prechecked?
mustn't they have prechecked? 	mustn't I have been prechecking?
mustn't you have been prechecking?
mustn't he have been prechecking?
mustn't we have been prechecking?
mustn't you have been prechecking?
mustn't they have been prechecking?