can countersink
Irregular verb: countersink - countersank- countersunk

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can countersink
you can countersink
she can countersink
we can countersink
you can countersink
they can countersink 	I can be countersinking
you can be countersinking
she can be countersinking
we can be countersinking
you can be countersinking
they can be countersinking	I can have countersunk
you can have countersunk
she can have countersunk
we can have countersunk
you can have countersunk
they can have countersunk	I can have been countersinking
you can have been countersinking
she can have been countersinking
we can have been countersinking
you can have been countersinking
they can have been countersinking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot countersink
you cannot countersink
she cannot countersink
we cannot countersink
you cannot countersink
they cannot countersink 	I cannot be countersinking
you cannot be countersinking
she cannot be countersinking
we cannot be countersinking
you cannot be countersinking
they cannot be countersinking	I cannot have countersunk
you cannot have countersunk
she cannot have countersunk
we cannot have countersunk
you cannot have countersunk
they cannot have countersunk	I cannot have been countersinking
you cannot have been countersinking
she cannot have been countersinking
we cannot have been countersinking
you cannot have been countersinking
they cannot have been countersinking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I countersink?
can you countersink?
can she countersink?
can we countersink?
can you countersink?
can they countersink? 	can I be countersinking?
can you be countersinking?
can she be countersinking?
can we be countersinking?
can you be countersinking?
can they be countersinking? 	can I have countersunk?
can you have countersunk?
can she have countersunk?
can we have countersunk?
can you have countersunk?
can they have countersunk? 	can I have been countersinking?
can you have been countersinking?
can she have been countersinking?
can we have been countersinking?
can you have been countersinking?
can they have been countersinking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not countersink?
can you not countersink?
can she not countersink?
can we not countersink?
can you not countersink?
can they not countersink? 	can I not be countersinking?
can you not be countersinking?
can she not be countersinking?
can we not be countersinking?
can you not be countersinking?
can they not be countersinking? 	can I not have countersunk?
can you not have countersunk?
can she not have countersunk?
can we not have countersunk?
can you not have countersunk?
can they not have countersunk? 	can I not have been countersinking?
can you not have been countersinking?
can she not have been countersinking?
can we not have been countersinking?
can you not have been countersinking?
can they not have been countersinking?