must countersink
Verbe irrégulier : countersink - countersank- countersunk

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must countersink
you must countersink
he must countersink
we must countersink
you must countersink
they must countersink 	I must be countersinking
you must be countersinking
he must be countersinking
we must be countersinking
you must be countersinking
they must be countersinking	I must have countersunk
you must have countersunk
he must have countersunk
we must have countersunk
you must have countersunk
they must have countersunk	I must have been countersinking
you must have been countersinking
he must have been countersinking
we must have been countersinking
you must have been countersinking
they must have been countersinking	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't countersink
you mustn't countersink
he mustn't countersink
we mustn't countersink
you mustn't countersink
they mustn't countersink 	I mustn't be countersinking
you mustn't be countersinking
he mustn't be countersinking
we mustn't be countersinking
you mustn't be countersinking
they mustn't be countersinking	I mustn't have countersunk
you mustn't have countersunk
he mustn't have countersunk
we mustn't have countersunk
you mustn't have countersunk
they mustn't have countersunk	I mustn't have been countersinking
you mustn't have been countersinking
he mustn't have been countersinking
we mustn't have been countersinking
you mustn't have been countersinking
they mustn't have been countersinking	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I countersink?
must you countersink?
must he countersink?
must we countersink?
must you countersink?
must they countersink? 	must I be countersinking?
must you be countersinking?
must he be countersinking?
must we be countersinking?
must you be countersinking?
must they be countersinking? 	must I have countersunk?
must you have countersunk?
must he have countersunk?
must we have countersunk?
must you have countersunk?
must they have countersunk? 	must I have been countersinking?
must you have been countersinking?
must he have been countersinking?
must we have been countersinking?
must you have been countersinking?
must they have been countersinking? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I countersink?
mustn't you countersink?
mustn't he countersink?
mustn't we countersink?
mustn't you countersink?
mustn't they countersink? 	mustn't I be countersinking?
mustn't you be countersinking?
mustn't he be countersinking?
mustn't we be countersinking?
mustn't you be countersinking?
mustn't they be countersinking? 	mustn't I have countersunk?
mustn't you have countersunk?
mustn't he have countersunk?
mustn't we have countersunk?
mustn't you have countersunk?
mustn't they have countersunk? 	mustn't I have been countersinking?
mustn't you have been countersinking?
mustn't he have been countersinking?
mustn't we have been countersinking?
mustn't you have been countersinking?
mustn't they have been countersinking?