could pump
Regular verb: pump - pumped- pumped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could pump
you could pump
he could pump
we could pump
you could pump
they could pump 	I could be pumping
you could be pumping
he could be pumping
we could be pumping
you could be pumping
they could be pumping	I could have pumped
you could have pumped
he could have pumped
we could have pumped
you could have pumped
they could have pumped	I could have been pumping
you could have been pumping
he could have been pumping
we could have been pumping
you could have been pumping
they could have been pumping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not pump
you could not pump
he could not pump
we could not pump
you could not pump
they could not pump 	I could not be pumping
you could not be pumping
he could not be pumping
we could not be pumping
you could not be pumping
they could not be pumping	I could not have pumped
you could not have pumped
he could not have pumped
we could not have pumped
you could not have pumped
they could not have pumped	I could not have been pumping
you could not have been pumping
he could not have been pumping
we could not have been pumping
you could not have been pumping
they could not have been pumping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I pump?
could you pump?
could he pump?
could we pump?
could you pump?
could they pump? 	could I be pumping?
could you be pumping?
could he be pumping?
could we be pumping?
could you be pumping?
could they be pumping? 	could I have pumped?
could you have pumped?
could he have pumped?
could we have pumped?
could you have pumped?
could they have pumped? 	could I have been pumping?
could you have been pumping?
could he have been pumping?
could we have been pumping?
could you have been pumping?
could they have been pumping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not pump?
could you not pump?
could he not pump?
could we not pump?
could you not pump?
could they not pump? 	could I not be pumping?
could you not be pumping?
could he not be pumping?
could we not be pumping?
could you not be pumping?
could they not be pumping? 	could I not have pumped?
could you not have pumped?
could he not have pumped?
could we not have pumped?
could you not have pumped?
could they not have pumped? 	could I not have been pumping?
could you not have been pumping?
could he not have been pumping?
could we not have been pumping?
could you not have been pumping?
could they not have been pumping?