English verb conjugation
COULD COUNTERSINK

Irregular verb: countersink - countersank - countersunk

Affirmation

Simple form	V-ing form
I could countersink you could countersink he could countersink we could countersink you could countersink they could countersink	I could be countersinking you could be countersinking he could be countersinking we could be countersinking you could be countersinking they could be countersinking
Perfect	V-ing perfect
I could have countersunk you could have countersunk he could have countersunk we could have countersunk you could have countersunk they could have countersunk	I could have been countersinking you could have been countersinking he could have been countersinking we could have been countersinking you could have been countersinking they could have been countersinking

Negation

Simple form	V-ing form
I could not countersink you could not countersink he could not countersink we could not countersink you could not countersink they could not countersink	I could not be countersinking you could not be countersinking he could not be countersinking we could not be countersinking you could not be countersinking they could not be countersinking
Perfect	V-ing perfect
I could not have countersunk you could not have countersunk he could not have countersunk we could not have countersunk you could not have countersunk they could not have countersunk	I could not have been countersinking you could not have been countersinking he could not have been countersinking we could not have been countersinking you could not have been countersinking they could not have been countersinking

Interrogative form

Simple form	V-ing form
could I countersink? could you countersink? could he countersink? could we countersink? could you countersink? could they countersink?	could I be countersinking? could you be countersinking? could he be countersinking? could we be countersinking? could you be countersinking? could they be countersinking?
Perfect	V-ing perfect
could I have countersunk? could you have countersunk? could he have countersunk? could we have countersunk? could you have countersunk? could they have countersunk?	could I have been countersinking? could you have been countersinking? could he have been countersinking? could we have been countersinking? could you have been countersinking? could they have been countersinking?

Interro-negative form

Simple form	V-ing form
could I not countersink? could you not countersink? could he not countersink? could we not countersink? could you not countersink? could they not countersink?	could I not be countersinking? could you not be countersinking? could he not be countersinking? could we not be countersinking? could you not be countersinking? could they not be countersinking?
Perfect	V-ing perfect
could I not have countersunk? could you not have countersunk? could he not have countersunk? could we not have countersunk? could you not have countersunk? could they not have countersunk?	could I not have been countersinking? could you not have been countersinking? could he not have been countersinking? could we not have been countersinking? could you not have been countersinking? could they not have been countersinking?