English verb conjugation
COULD COUNTERCHECK

Regular verb: countercheck - counterchecked - counterchecked

Affirmation

Simple form	V-ing form
I could countercheck you could countercheck he could countercheck we could countercheck you could countercheck they could countercheck	I could be counterchecking you could be counterchecking he could be counterchecking we could be counterchecking you could be counterchecking they could be counterchecking
Perfect	V-ing perfect
I could have counterchecked you could have counterchecked he could have counterchecked we could have counterchecked you could have counterchecked they could have counterchecked	I could have been counterchecking you could have been counterchecking he could have been counterchecking we could have been counterchecking you could have been counterchecking they could have been counterchecking

Negation

Simple form	V-ing form
I could not countercheck you could not countercheck he could not countercheck we could not countercheck you could not countercheck they could not countercheck	I could not be counterchecking you could not be counterchecking he could not be counterchecking we could not be counterchecking you could not be counterchecking they could not be counterchecking
Perfect	V-ing perfect
I could not have counterchecked you could not have counterchecked he could not have counterchecked we could not have counterchecked you could not have counterchecked they could not have counterchecked	I could not have been counterchecking you could not have been counterchecking he could not have been counterchecking we could not have been counterchecking you could not have been counterchecking they could not have been counterchecking

Interrogative form

Simple form	V-ing form
could I countercheck? could you countercheck? could he countercheck? could we countercheck? could you countercheck? could they countercheck?	could I be counterchecking? could you be counterchecking? could he be counterchecking? could we be counterchecking? could you be counterchecking? could they be counterchecking?
Perfect	V-ing perfect
could I have counterchecked? could you have counterchecked? could he have counterchecked? could we have counterchecked? could you have counterchecked? could they have counterchecked?	could I have been counterchecking? could you have been counterchecking? could he have been counterchecking? could we have been counterchecking? could you have been counterchecking? could they have been counterchecking?

Interro-negative form

Simple form	V-ing form
could I not countercheck? could you not countercheck? could he not countercheck? could we not countercheck? could you not countercheck? could they not countercheck?	could I not be counterchecking? could you not be counterchecking? could he not be counterchecking? could we not be counterchecking? could you not be counterchecking? could they not be counterchecking?
Perfect	V-ing perfect
could I not have counterchecked? could you not have counterchecked? could he not have counterchecked? could we not have counterchecked? could you not have counterchecked? could they not have counterchecked?	could I not have been counterchecking? could you not have been counterchecking? could he not have been counterchecking? could we not have been counterchecking? could you not have been counterchecking? could they not have been counterchecking?