English verb conjugation
COULD TANK

Regular verb: tank - tanked - tanked

Affirmation

Simple form	V-ing form
I could tank you could tank he could tank we could tank you could tank they could tank	I could be tanking you could be tanking he could be tanking we could be tanking you could be tanking they could be tanking
Perfect	V-ing perfect
I could have tanked you could have tanked he could have tanked we could have tanked you could have tanked they could have tanked	I could have been tanking you could have been tanking he could have been tanking we could have been tanking you could have been tanking they could have been tanking

Negation

Simple form	V-ing form
I could not tank you could not tank he could not tank we could not tank you could not tank they could not tank	I could not be tanking you could not be tanking he could not be tanking we could not be tanking you could not be tanking they could not be tanking
Perfect	V-ing perfect
I could not have tanked you could not have tanked he could not have tanked we could not have tanked you could not have tanked they could not have tanked	I could not have been tanking you could not have been tanking he could not have been tanking we could not have been tanking you could not have been tanking they could not have been tanking

Interrogative form

Simple form	V-ing form
could I tank? could you tank? could he tank? could we tank? could you tank? could they tank?	could I be tanking? could you be tanking? could he be tanking? could we be tanking? could you be tanking? could they be tanking?
Perfect	V-ing perfect
could I have tanked? could you have tanked? could he have tanked? could we have tanked? could you have tanked? could they have tanked?	could I have been tanking? could you have been tanking? could he have been tanking? could we have been tanking? could you have been tanking? could they have been tanking?

Interro-negative form

Simple form	V-ing form
could I not tank? could you not tank? could he not tank? could we not tank? could you not tank? could they not tank?	could I not be tanking? could you not be tanking? could he not be tanking? could we not be tanking? could you not be tanking? could they not be tanking?
Perfect	V-ing perfect
could I not have tanked? could you not have tanked? could he not have tanked? could we not have tanked? could you not have tanked? could they not have tanked?	could I not have been tanking? could you not have been tanking? could he not have been tanking? could we not have been tanking? could you not have been tanking? could they not have been tanking?