English verb conjugation
COULD SUBSERVE

Regular verb: subserve - subserved - subserved

Affirmation

Simple form	V-ing form
I could subserve you could subserve he could subserve we could subserve you could subserve they could subserve	I could be subserving you could be subserving he could be subserving we could be subserving you could be subserving they could be subserving
Perfect	V-ing perfect
I could have subserved you could have subserved he could have subserved we could have subserved you could have subserved they could have subserved	I could have been subserving you could have been subserving he could have been subserving we could have been subserving you could have been subserving they could have been subserving

Negation

Simple form	V-ing form
I could not subserve you could not subserve he could not subserve we could not subserve you could not subserve they could not subserve	I could not be subserving you could not be subserving he could not be subserving we could not be subserving you could not be subserving they could not be subserving
Perfect	V-ing perfect
I could not have subserved you could not have subserved he could not have subserved we could not have subserved you could not have subserved they could not have subserved	I could not have been subserving you could not have been subserving he could not have been subserving we could not have been subserving you could not have been subserving they could not have been subserving

Interrogative form

Simple form	V-ing form
could I subserve? could you subserve? could he subserve? could we subserve? could you subserve? could they subserve?	could I be subserving? could you be subserving? could he be subserving? could we be subserving? could you be subserving? could they be subserving?
Perfect	V-ing perfect
could I have subserved? could you have subserved? could he have subserved? could we have subserved? could you have subserved? could they have subserved?	could I have been subserving? could you have been subserving? could he have been subserving? could we have been subserving? could you have been subserving? could they have been subserving?

Interro-negative form

Simple form	V-ing form
could I not subserve? could you not subserve? could he not subserve? could we not subserve? could you not subserve? could they not subserve?	could I not be subserving? could you not be subserving? could he not be subserving? could we not be subserving? could you not be subserving? could they not be subserving?
Perfect	V-ing perfect
could I not have subserved? could you not have subserved? could he not have subserved? could we not have subserved? could you not have subserved? could they not have subserved?	could I not have been subserving? could you not have been subserving? could he not have been subserving? could we not have been subserving? could you not have been subserving? could they not have been subserving?