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 must not countercheck
you must not countercheck
he must not countercheck
we must not countercheck
you must not countercheck
they must not countercheck 	I must not be counterchecking
you must not be counterchecking
he must not be counterchecking
we must not be counterchecking
you must not be counterchecking
they must not be counterchecking	I must not have counterchecked
you must not have counterchecked
he must not have counterchecked
we must not have counterchecked
you must not have counterchecked
they must not have counterchecked	I must not have been counterchecking
you must not have been counterchecking
he must not have been counterchecking
we must not have been counterchecking
you must not have been counterchecking
they must not 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 	
must I not countercheck?
must you not countercheck?
must he not countercheck?
must we not countercheck?
must you not countercheck?
must they not countercheck? 	must I not be counterchecking?
must you not be counterchecking?
must he not be counterchecking?
must we not be counterchecking?
must you not be counterchecking?
must they not be counterchecking? 	must I not have counterchecked?
must you not have counterchecked?
must he not have counterchecked?
must we not have counterchecked?
must you not have counterchecked?
must they not have counterchecked? 	must I not have been counterchecking?
must you not have been counterchecking?
must he not have been counterchecking?
must we not have been counterchecking?
must you not have been counterchecking?
must they not have been counterchecking?