must countercheck
Verbe régulier : countercheck - counterchecked- counterchecked

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must countercheck
you must countercheck
he must countercheck
we must countercheck
you must countercheck
they must countercheck 	I must be counterchecking
you must be counterchecking
he must be counterchecking
we must be counterchecking
you must be counterchecking
they must be counterchecking	I must have counterchecked
you must have counterchecked
he must have counterchecked
we must have counterchecked
you must have counterchecked
they must have counterchecked	I must have been counterchecking
you must have been counterchecking
he must have been counterchecking
we must have been counterchecking
you must have been counterchecking
they must have been counterchecking	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't countercheck
you mustn't countercheck
he mustn't countercheck
we mustn't countercheck
you mustn't countercheck
they mustn't countercheck 	I mustn't be counterchecking
you mustn't be counterchecking
he mustn't be counterchecking
we mustn't be counterchecking
you mustn't be counterchecking
they mustn't be counterchecking	I mustn't have counterchecked
you mustn't have counterchecked
he mustn't have counterchecked
we mustn't have counterchecked
you mustn't have counterchecked
they mustn't have counterchecked	I mustn't have been counterchecking
you mustn't have been counterchecking
he mustn't have been counterchecking
we mustn't have been counterchecking
you mustn't have been counterchecking
they mustn't have been counterchecking	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I countercheck?
must you countercheck?
must he countercheck?
must we countercheck?
must you countercheck?
must they countercheck? 	must I be counterchecking?
must you be counterchecking?
must he be counterchecking?
must we be counterchecking?
must you be counterchecking?
must they be counterchecking? 	must I have counterchecked?
must you have counterchecked?
must he have counterchecked?
must we have counterchecked?
must you have counterchecked?
must they have counterchecked? 	must I have been counterchecking?
must you have been counterchecking?
must he have been counterchecking?
must we have been counterchecking?
must you have been counterchecking?
must they have been counterchecking? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I countercheck?
mustn't you countercheck?
mustn't he countercheck?
mustn't we countercheck?
mustn't you countercheck?
mustn't they countercheck? 	mustn't I be counterchecking?
mustn't you be counterchecking?
mustn't he be counterchecking?
mustn't we be counterchecking?
mustn't you be counterchecking?
mustn't they be counterchecking? 	mustn't I have counterchecked?
mustn't you have counterchecked?
mustn't he have counterchecked?
mustn't we have counterchecked?
mustn't you have counterchecked?
mustn't they have counterchecked? 	mustn't I have been counterchecking?
mustn't you have been counterchecking?
mustn't he have been counterchecking?
mustn't we have been counterchecking?
mustn't you have been counterchecking?
mustn't they have been counterchecking?